How parents describe the positive aspects of parenting their child who has intellectual disabilities: A systematic review and narrative synthesis

Abstract Background Identifying what parents describe to be positive about parenting their child who has intellectual disabilities is important for professional practice and how parents can be supported over a lifespan. Methods Studies in which parents describe the positive aspects of parenting their child with intellectual disabilities were identified via electronic databases searches and analysed in a narrative synthesis. Results Twenty‐two studies were included. Consistent themes emerged relating to positive change, increased personal strength, growth and development largely related to parental intrapersonal orientation. Several studies emphasized that the presence of growth or positive change does not imply the absence of distress. Conclusions Positive aspects are not consistently defined and measured differently across studies. Consistent themes are described variously attributed to theories relating to coping, adaptation or growth following adversity; however, no single theoretical framework emerged. Factors likely to predict a parent's ability to identify positive aspects are inconclusive.


| BACKG ROU N D
Most children with intellectual disabilities live at home with their parents. In addition, there are estimates that in England between 35% and 87% of adults with an intellectual disability also live at home and are supported by their parents, families or friends (Copeland, 2012;Hatton et al., 2014;NHS Digital, 2015), and similarly, in the USA around 78% of adults are estimated to live with family members (The Arc, 2011).
Most research on parenting a child with an intellectual disability is typically framed within a stress-coping paradigm in which the child (or their characteristics) is "the stressor" and a the parent or family is reported as coping with a negative impact or burden from the child's impairment(s) (Hastings, Daley, Burns, & Beck, 2006;McConnell & Savage, 2015). This includes higher overall levels of poor physical, mental health and mental well-being compared to parents of typically developing children (NHS England et al., 2016) with these poor outcomes increasing with the duration and intensity of the "caring" role (DOH, 2010;Neece & Baker, 2008).
These parents also face socio-economic disadvantage which includes increased risk of poverty, stigma and social exclusion (Emerson, 2012;Joseph Rowntree Foundation, 2016).
Whilst the stress that comes with parenting a child with intellectual disabilities is undeniable, this focus on a pathological model represents only one perspective and several studies report that carers can experience both stress and positive experiences simultaneously (Baker et al., 2003;Hastings et al., 2006;Patton, Ware, McPherson, Emerson, & Lennox, 2016). Although initially dismissed as denial, an attempt to alleviate their guilt or a defensive reaction (Behr, 1990;Wikler, Wasow, & Hatfield, 1983) the past twenty years has seen a growing body of literature which has recognized the positive effects and contributions that the child brings to the parents and family. However, in some studies, positive aspects are inferred only by the absence of negative affect, stress and depression (Miersschaut, Roeyers, & Warreyn, 2010;Van de Veek, Kraaij, & Garnefski, 2009).
There is no single theoretical model which addresses the idea of "positivity" in parenting a child with intellectual disabilities (Beighton & Wills, 2017;Blacher & Baker, 2007) although several different conceptual models have been proposed in general studies (Table 1). These illustrate different theoretical and ontological positions about positivity and whether it reflects a coping process (Park, 2010(Park, , 2013Park & Folkman, 1997;Taylor, 1983) or is post-traumatic (PTG) or adversarial growth (Hobfoll et al., 2007;Joseph & Linley, 2005;Maercker & Zoellner, 2004;Schaefer & Moos, 1998;Tedeschi & Calhoun, 1995. However, one commonality is that most of the theoretical models require individuals to use cognitive coping/ processing to construct meaning from their experiences. There is no accepted definition of a positive aspect. However, it has been described as situations where the person appraises caregiving as "enhancing or enriching their life" (Kramer, 1997:219). Positive aspects have been investigated in other carer groups, for example in those caring for people with cancer (Hudson, 2004), stroke (Mackenzie & Greenwood, 2012), Alzheimer's disease (Cheng, Mak, Lau, Ng, & Lam, 2015), dementia (Lloyd, Patterson, & Muers, 2014) and developmental disabilities (Manor-Binyamini, 2016;Strecker, Hazelwood, & Shakespeare-Finch, 2014). Caregivers who report positive aspects have been found to have better self-reported health, less depressive symptoms, higher caregiving competence and greater family adjustment (Basu, Hochhalter, & Stevens, 2015;Cheng, Lam, Kwok, Ng, & Fung, 2013;Pinquart & Sörensen, 2004;Trute, Benzies, Worthington, Reddon, & Moore, 2010). The parent of a child with intellectual disabilities may, however, experience positive aspects differently to other carer groups as they provide lifelong support for their child compared to the 3-15 years of exposure to physical and psychosocial demands faced, for example, by those caring for a person TA B L E 1 Theoretical models of positivity

Coping models
Coping with adverse events model/Stress related growth and thriving/meaning making model (Park, 2010(Park, , 2013 with Alzheimer's disease (Vitaliano, Zhang, & Scanlan, 2003). Therefore, it is important to explore whether positive aspects are reported similarly in this parent group.

| AIM OF RE VIE W
The aim of this review is to identify what parents describe to be positive about parenting a child with intellectual disabilities by undertaking a systematic review and narrative synthesis of primary research. A secondary aim is to identify the range of factors that may contribute to parental positive perceptions. Bringing together the evidence on such positive aspects has important implications for professional practice in how it supports parents to be able to continue caring over the lifespan.
The terms child and children are used throughout this review to represent both children and adult children.

| ME THODS
The decisions regarding the search strategy and inclusion criteria, study selection, data extraction, quality assessment and data synthesis are outlined following guidance from the Centre for Reviews and Dissemination (Centre for Reviews & Dissemination, 2008).

| Search strategy
An Internet-based bibliographic database search was initially con- British Nursing Index (BNI), Biomed Central and Internurse. As the review was not exploring intervention studies, a PEO framework (population, exposure and outcome) was utilized (Booth, 2006) and Boolean operators were used to combine terms for parent/carer and parenting/caring for a child with an intellectual disability and synonyms used for positive aspects were identified from literature which explored positive aspects in other carer groups (as described previously). No methodological filter was applied. An example of one search string undertaken on the CINAHL Plus database is shown in Table 2.
Ancillary searching included using the Mendeley academic network, reference lists and citation trails from the included papers, and authors with published work in the field were also contacted. Grey literature and non-peer-reviewed studies were excluded. Studies in which positive experiences or impact of parenting were described were included if the positive aspects were described narratively and identified as findings in the abstract. The inclusion and exclusion criteria for the literature search are shown in Table 3.

| Screening and data extraction
Eligibility for full-text retrieval was ascertained by screening the titles and abstracts according to the inclusion/exclusion criteria and was carried out independently by two reviewers. Three disagreements were resolved through discussion, and for one study, it was necessary to involve a third reviewer. Full texts were screened against the same criteria.
A data extraction form was developed and piloted with two studies. Data extracted included authors, study design, methodology, country of publication, the participant and child characteristics and the positive aspects identified.

| Data analysis
Data were analysed using a textual narrative approach and thematic analysis, which is particularly suitable for identifying the main, recurrent and or most important themes (based on the review question) and provides a possible structure for new research (Lucas, Baird, Arai, Law, & Roberts, 2007). The characteristics of positive aspects reported were summarized using words and text within individual studies and then between all included studies. This data were then grouped into meaningful themes (Thomas, Harden, & Newman, 2012).

| Quality assessment
Critical appraisal and assessment of quality of the included studies were carried out by three researchers and any queries discussed  (Lucas et al., 2007;Joanna Briggs Institute, 2014); therefore, each article was assessed independently and no composite score for quality was made as recommended by the Cochrane methods panel (Higgins, Altman, & Sterne, 2011). A checklist (National Collaborating Centre for Methods & Tools, 2003) adapted by Greenwood, Mackenzie, Cloud, and Wilson (2008) which had been used in a systematic review on positive experiences of caregiving in stroke (Mackenzie & Greenwood, 2012) was used to interrogate the quantitative studies for their potential sources of bias (selection, measurement and confounding) and the credibility of the discussion and conclusion. Each study was considered to be of low, medium or high risk of bias, but no articles were excluded on this basis. Qualitative studies were interrogated using an adapted checklist from criteria outlined by Popay, Rogers, and Williams (1998) and adapted by Greenwood, Mackenzie, Cloud, and Wilson (2009) for use in studies of carers of stroke survivors which screened for integrity, transparency and transferability. These were considered to be "of quality" or "of a lower quality."

| RE SULTS
The initial database literature searches and contacting authors identified 3,703 articles for review. Following screening of the titles and abstracts and removal of duplicates, 93 full-text articles were obtained and reference lists from these studies were also handsearched for other relevant studies (Greenhalgh, 2005) and eight additional articles were found. Twenty-two studies were found to be eligible for inclusion and were retained following application of the review criteria screening criteria. The main reason why studies were excluded (n = 37) was due to the children in the sample not having a clear diagnosis of intellectual disabilities or the results not reported separately when included in a mixed sample of children with developmental disabilities. Supplementary file 1 shows the 81 studies which were excluded. Figure 1 shows a flow diagram of the study selection process.

| Characteristics of the included studies
Characteristics of the included studies are shown in Table 4. These will be referred to by their assigned study number here forward and are categorized by study design.
Seven qualitative studies were included, one was pluralistic evaluation which illustrated the quantitative findings with a qualitative case study and one used a mixed methodology study which ascertained the positive aspects from only qualitative interviews.
Although eleven quantitative studies were included, four included open-ended questions with two reporting both the quantitative and qualitative responses (8,9) and two reported just the findings from the open-ended questions (10,11). One quantitative study supplemented their results with quotes taken from an earlier qualitative study (7), and a review was included in which the authors reported a previously discounted "positive" finding from a study they had undertaken which explored chronic sorrow in families with a mentally retarded child (22).
The majority of studies originated from high-income countries, with two undertaken in low-and middle-income countries, Pakistan and Southern India (5,19). One UK study obtained responses from seven countries although most (41/48) were predominantly from within the United Kingdom (18).

Inclusion criteria
Study has a primary focus on how parents describe the "positive aspects" of parenting a child with an intellectual disability Describes the experiences, perceptions and views of primary carers (i.e., parents & family, not paid carers) for a child/adult child (of any age) who has a primary diagnosis of intellectual disability The child lives at home with the parent

Published in English language
Any study design

Exclusion criteria
Positive aspects are not described by the parents (i.e., scores are reported, correlations and relationships explored or hypotheses tested) Positive aspects only briefly mentioned The child has autism spectrum disorder (ASD), pervasive developmental disorder or developmental delay/disabilities without a primary diagnosis of intellectual disability The study includes a variety of children with developmental delays/developmental disabilities and results/findings are not reported separately The child lives in residential or supported accommodation Not published in English language Table 4 shows the methodologies, instruments/scales and questions used to measure and ascertain the positive aspects. It also shows the many varied terms the authors used to report the positive aspects. All eleven quantitative studies, the pluralistic evaluation and mixed methodology study were of a cross-sectional design using questionnaire surveys which were self-administered except for three which used a researcher to complete the questionnaire with the participant (1,4,5). The most commonly used scale was the Positive Contribution Scale (PCS), a subsection of the Kansas Inventory of Positive Perceptions (KIPP) designed specifically to assess the families' cognitive perceptions about their child with a disability (Behr, Murphy, & Summers, 1992). The scale consists of nine independent subsections, and although administered in five F I G U R E 1 Flow diagram of the summary of the study selection process (Moher et al., 2015)  • The positive impact of the child itself (happiness and fulfilment) and its effect on the family in general (strength and family closeness) was positively predicted by the use of reframing coping strategies (p 0.001). • Mothers reporting higher levels of caregiving demand reported more personal growth and maturity (p = 0.018) • Reframing was also a positive predictor of positive effects on the mother herself (personal growth and maturity) (p = 0.035) • Source of strength and family closeness (p = 0.004) Expanded social network (p = 0.003) Fathers reported more positive perceptions than mothers on one scale: • Source of pride and cooperation (p = 0.046) Low risk of bias N = 36 n = 20 (56%) male, n = 16 (44%) female 5-8 years old (mean age 6 years) Intellectual disability: 31% Mild 53% Moderate 16% severe/profound Agreement or strong agreement using self-rated PCS scales on "the child is a...": • Source of happiness or fulfilment (78%) • Source of strength and family closeness (75%) • Source of personal growth and maturity (58%) Semi-structured group interviews and constant comparative methods of analysis (Glaser & Strauss, 1967). "What are the positive impacts you feel your son or daughter with an intellectual disability has had on your family?" Reports "positive impact" Semi-structured interviews and a thematic analysis (Flick, 1998) Question not specified other than including the positive aspects of raising a child with Williams syndrome Reports "positive impact"

21
6 mother and father pairs, remainder mothers 16 King et al. (2011) To examine the nature of the benefits seen by parents of children with ASD and Down syndrome (differences between children at elementary and high school)* Two semi-structured interviews 2-5 months apart using a grounded theory approach (Strauss & Corbin, 1998) "Have your family values, priorities and worldviews changed over time?" "What sort of things do you celebrate?" Reports "benefits" Rewards emerging from the interpersonal dynamic (carer and the child) Pleasure seeing relative happy, maintaining dignity of relative, expression of love, brought closer to relative, closer family ties, appreciation from others, relative does not complain Rewards derived primarily from the intrapersonal orientation of the carer: seeing needs attended to, seeing relative well turned out, knowing I've done my best, altruism, provides a challenge, feel needed/wanted, test own abilities, fulfilling duty, providing a purpose in life, stop feeling guilty Rewards stemming from a desire to promote a positive outcome for the person with ID: Help relative overcome difficulties, see small improvements in condition, keep relative out of institution, give best care possible, help reach full potential, developed new skills/abilities, less selfish, widened interests.

Medium risk of bias
Aged 0 to 35 years 7 (63%) female 4 (27%) male Self-reported degrees of intellectual disability ranged from low to high Six of these studies had at least one primary aim that focussed on either exploring the parent's positive perceptions of the positive contribution the child had brought to the parent or family or the factors relating to positive outcomes, that is coping differences in perceived positives between mothers and fathers (2, 3, 4, 6, 8,11).
One study explored the phenomenon in mothers who had multiple children with intellectual disabilities (17).
Three qualitative studies had primary aims to examine or explore the positive aspects of caring and used positively phrased questions (13,19,20) whilst four explored the experiences or impact by asking similar neutral questions (14,16,17,18,21). The questions were not specified in two studies (12, 15).  (Peshawaria, 2000). Scale was administered to study the negative impacts only. Positive impacts were ascertained from focus groups and in-depth interviews. Type of thematic analysis undertaken not provided "What were the good changes that have happened to you since this child came into your life?" Reports "positive impacts" The author is reporting a previously discounted "positive" finding from a study they had undertaken which explored adjustment in families with a mentally retarded child (Wikler et al., 1981) Original study -Questionnaire survey Reports "strengths"

| Quality of the included studies
The quality grading of the studies is shown in Table 4 as an overall assessment. In the quantitative studies, validity and reliability were affected in studies considered to be of a medium risk of bias as they did not report methods clearly enough to replicate the study (12), used modified instruments without explanations of what was changed or details of piloting (8,10). The two studies that had small sample sizes might lack statistical power, and therefore, their results should be viewed with caution (2,4). Studies also included selection/sample bias, that is recruiting friends and acquaintances of the first author (10) and staff selecting "good copers" to participate (7).

Questionnaire surveys completed by researchers for parents may
have also introduced social desirability bias (1,4,5), and an honorarium was paid for return of the completed questionnaires distributed at a specialist school (3).

Quality Assessment risk of bias
No demographic details collected The "positive impact" was identified as one of four thematic groupings: No details provided • 75% (n = 27) of parents reported they had become "stronger," of these 46% (n = 12) felt "much stronger" (Original study -medium risk of bias)

BEIGHTON aNd WILLS
Six qualitative studies and the mixed methodology study (20) were considered to be of quality as all had some degree of reflexivity about why they were investigating this topic and had clear research questions, aims and theoretical underpinnings for the qualitative methodologies used. Reliability was demonstrated by detailed Methods sections, and three studies described memberchecking of the analyses by other researchers (13,15,19,21) with the latter two studies sending out the transcripts for checking by the parents for accuracy and comments. Three did not, however, fully describe the participants' characteristics (13,14,15), and another introduced selection bias as they relied on parent group leaders and service providers to nominate families who would fit the criteria and be able provide a wide range of perspectives (16).
The pluralistic evaluation (12) was considered to be of lower quality as the quantitative findings were supplemented by only one qualitative case study, a limitation acknowledged by the authors.

| Theoretical frameworks
The majority of studies discussed findings of positive perceptions in relation to stress, burden, coping and adaptation although not explicitly presenting a theoretical framework. All except two of the studies were atheoretical (4,5). Study 4 used an adapted version of the "working model for the study of families positive perceptions" (Hastings & Taunt, 2002). However, their findings showed that this model had reduced explanatory powers and proposed that the findings instead provided evidence for "positive psychology." Study 5 proposed the two-factor model of caregiving to explain the coexistence of positive and negative outcomes (Lawton, Moss, Kleban, Glicksman, & Rovine, 1991).

| SYNTHE S IS OF THE RE SULTS
Because parent or child characteristics may influence whether and the extent to which positive aspects of caring may be reported, these are summarized here:

| Parental and child characteristics
The parents were predominantly married/cohabiting Caucasian mothers, the majority being between 35 and 50 years of age. Five studies contained mothers only (1,2,4,5,17), and three studies contained a small number of non-biological parents, but results were not broken down to explore differences in parental positivity (4,7,9).
None of the studies reported the length of time the parents (biological, adoptive parents, guardians and stepmothers) had supported the child but it cannot be assumed they parented them from birth.
Although income details were provided in four studies (5,8,9,13), these were not comparable due to the age of the studies and being from different countries. As a high proportion of parents attended higher education institutions and were employed outside the home, it may be assumed that they were from higher socio-economic groups.
The ages of the children they parented ranged from birth to age 55. The majority of studies were conducted with parents of children aged 19 years and under (mean/average age ranged from 3 to 11 years) (2,3,4,5,6,8,10,11,14,16,17,21), six contained both children and adult children (7,9,12,13,15,19), and one contained adult children only (1). No child characteristics were provided in three studies (18,20,22), and the latter study also failed to provide any details of the parents. Most studies contained a higher ratio of male children than female children with the majority having moderate to severe intellectual disabilities.

| Positive aspects
As shown in Table 4, twelve different terms were used by the authors to report the positive aspects, the most common being positive impact(s) (5,13,15,18,20). Only two studies were consistent in their operational definition and reported the positive aspect similarly. Study 11 defined what they were exploring as "the belief or conclusion that an adverse event or circumstance has revealed or evoked positive outcomes in one's life" (McCausland & Pakenham, 2003:854) and reported benefit finding. Study 1 (p580) used the "overall pleasure, satisfaction and sense of mental well-being that a person receives in her role as a caregiving parent" and reported gratifications.

| Thematic analysis
A narrative synthesis which synthesizes common elements across otherwise heterogeneous studies was undertaken. This method involves using a textual narrative approach and thematic analysis, which is particularly suitable for identifying the main, recurrent and or most important themes (based on the review question) and provides a possible structure for new research (Lucas et al., 2007). The characteristics of positive aspects reported in both qualitative and quantitative primary research studies were summarized using words and text within individual studies and then between all included studies. These data were then grouped into eight themes (Thomas et al., 2012), and the results are shown in

| FAC TOR S REL ATING TO PARENTAL P OS ITIVIT Y
Only two studies purposely investigated factors which predict the likelihood of a parent experiencing positive aspects (2,4). From other studies, other factors were identified which were found to have a relationship to parental positivity:

| Child characteristics
Certain child characteristics were found to affect the parent's ability to perceive things as positive. Parents whose children had fewer medical problems and learning difficulties reported a more positive outlook (11). A significant negative correlation was found between the severity of the child's behaviour, emotional problems, perceived care demand and the ability to identify positive aspects (4). A significant negative correlation was found in mothers with the greater the intellectual disability, the smaller number the positive perceptions reported, which was not evident in fathers (6). In contrast, the increased difficulty of care required for the child and mothers with higher caring demands emerged as a significant positive predictor for parents reporting personal growth and maturity in two studies (2,3). The studies contained children who had a range of intellectual disabilities; however, it should be recognized that they are not a homogenous group and it could be that different social and psychological factors are at play across different behavioural phenotypes.
Previous research has reported that parents of children with Down's syndrome experience more rewards compared to parents of children with other disabilities (Hodnapp et al., 2001). However, in the studies that contained samples of children who had Down's syndrome (7,9,16) the positives identified were similar to those identified in the other studies with one small exception; in two studies, improved or expanded relationships with others were not identified as a positive, but this may be due to the wording of the questions asked (7,9).
No differences were found in the study of parents of children with Down's syndrome and a comparison group of parents who have children with autism spectrum disorder (16).

| Culture
Despite a reported national culture of stigma and blame about having a child with an intellectual disability in these countries, mothers African American mothers reported slightly higher levels of gratifications and positive impacts than Caucasian/Anglo mothers after controlling for socio-economic status (educational levels and income) (1), and parent's who were of Hispanic origin and/or of a lower educational background who had children with Down's syndrome were more likely to report a positive outlook (9).

| Gender of the parent
Although the majority of the studies contained mothers, statistically significant differences between mothers and fathers in terms of total PCS scores were found. In the PCS subscale most closely

| Social support
The helpfulness of informal social support services and acquiring social support were found to be predictors of maternal positive perceptions (2), and having a husband or parent available to share the burden was found to have a significant influence on altering the mother's outlook to a positive one (17). All but four study parents reported improved and strengthened relationships with others, and this could lead to increased social support for both the parent and their child.

| Mental well-being
Higher levels of mental well-being and self-efficacy (p < 0.001) were associated with increased benefit finding in both mothers (p < 0.05) and fathers (p < 0.01) (8), and positive perceptions were found to coexist with symptoms of anxiety and depression in both fathers and mothers (6).

Pluralistic Evaluation/ mixed methods/ case study/ Review
Personal strength Confidence/more confident, personal growth, strength, personal growth and maturity, increased sense of purpose, more perseverance, more determined (refusing to give up until an acceptable outcome is achieved), belief in one's own inner strength, confronting each challenge.
2, 3,4,5,6,7,89,11 13,14,15,18,19 22 Personal development Becoming a better person, being less materialistic and selfish, more tolerance and patience, more open and honest, increased self-esteem, kinder, learning something about yourself, feeling good about yourself, learning to be positive, sense of fulfilment and pride, more hopeful, more optimistic, laugh more, career/job growth, developed new skills and made a difference through advocacy 1, 3,5,6,7,8,910,11 13, 14,15, 16,17,18,19 12,20 New outlook or perspective on life  3,5,6,7,8,9,11,14 13,14,15,16,17,18,19 20,21 The child as a source of happiness and fulfilment Child is a source of joy, happiness, pleasure, pride and fulfilment, enjoying being with the child, have a deep personal bond unlike any other, appreciating the "preciousness" of the child, grateful and lucky to have their children, the child is a source/expression of love and happiness, company for the parents, personal growth or improvements in their child's condition, unexpected achievements/accomplishments, small improvements in condition, watching the child achieve things never thought possible, child is a good luck charm 1,2,3,4,5,7, 9,10,11 13,14,15,16,17,18,19 12,20,21 Improved/ expanded relationships Increased family unity and closeness, support and expanded community networks/involvement, closer family ties/relationships, more meaningful relationships with others, improved social support/friendships, interacted and socialized with others they would otherwise have not met (i.e., parents of children with intellectual disabilities) meeting/helping other families, stronger marriage 2, 3,4,5,6,8,11 13,15,16,17,18 12,20,21 The positive effect the child has on others Child has a positive impact on siblings, siblings had become more caring, accepting, sensitive, understanding, considerate and mature, the child has a positive effect on others in the community, the child bringing joy to others. 7,8,9,10,11 13,15,17,18,19 20 Increased spirituality/ Religiosity Stronger inner faith and religious convictions, increased spiritual growth, child is blessing/angel from God,  with intellectual disabilities has on others was identified as a positive aspect and unique to these parents.
All except one of the studies included the review are from the last two decades. This is most likely because in most early studies positive aspects were not the focus combined with a shift away from placing children in institutional care and also a rise in the positive psychology movement from the 1990s. This is illustrated by the early study included in this review whereby the positive findings were initially discounted in a study exploring chronic sorrow (Wikler, Wasow, & Hatfield, 1981), with the authors later explaining that this was an example of a pervasive stance adopted among professionals in which the problems instead of the strengths were were "rarely seen as applicable" by parents, and therefore would have resulted in poor internal consistency (p162). This highlights that positive aspects are influenced by the ways in which the construct is measured yet the measurement tools themselves are informed by different epistemological views and models. This lack of clarity has led to a number of terms that are being used synonymously which appear to describe the same construct and some of which may be interrelated. It also indicates that objective measures alone are not sufficient to fully represent positive aspects in its entirety, consistent with the findings of Jess, Hastings, and Totsika (2017).
No differences were found between mothers and fathers reporting positive aspects. The parents included in the studies in this review were, however, predominantly married/cohabiting white mothers from a high socio-economic status. Due to the limited number of studies focusing on couples, the data obtained from mothers only provide an incomplete picture of parenting a child with an intellectual disability as fathers can have a different role within the family and may have a different relationship with the child. The high number of married mothers as participants could also mean that they are likely to have more social support from their spouse during times of stress and report feeling more positive, consistent with the stressbuffering hypothesis (Cohen & McKay, 1984). However, although a positive was that the child was perceived to have strengthened the parent's marriage, in contrast, 11% (104/943) of parents felt that their child with Down's syndrome had "uniquely" put a strain on their marriage (9). There could be differences in positive perceptions between lone parents and those who are married which would benefit from further exploration. Similarly, having higher socio-economic status may allow these parents the opportunity to pay for additional support and services, which may allow them to perceive things in a more positive light.
All but two of the studies were conducted in high-income countries where considerable support services are provided for families

Caring role
Keeping the child out of an institution, seeing them well turned out, helping them overcome difficulties, helping them to reach their full potential, doing a good job, gaining appreciation for their work, appreciation from the child and other family members, wanting to care more than a sense of duty, altruism, parenting role being a rewarding experience, pleasure seeing the child happy, maintaining dignity of the relative, seeing their needs attended to, feeling needed/wanted, testing own abilities, fulfilling duty, providing a purpose in life, giving the best care possible, a rewarding experience, absence of care demands 1,11 15 12 (Families Special Interest Research Group of IASSID, 2014). This is in contrast to low-or middle-income countries where <50% provide any support to families of children with intellectual disabilities in areas such as respite care, in-home support or advocacy (WHO, 2007).
Only studies published in English language were included, and the parents were predominantly Caucasian, which has limited the consideration of the contribution of different cultural traditions and expectations and which merits further investigation as ethnicity was found to have an influence on parental positive aspects. Five quantitative studies used the PCS subscale of "strength and family closeness" (2,3,4,5,6); however, although most were in agreement or strong agreement that their child was a source of strength and family closeness (4), the mean score for family closeness in mothers from Pakistan ranked very low, seventh out of nine subscales (5). The findings of study 1 were consistent with studies of Latina mothers of children with intellectual disabilities (that did not meet the inclusion criteria), which report slightly higher levels of gratifications and positive impacts than Anglo mothers (Blacher & Baker, 2007;Blacher, Begum, Marcoulides, & Baker, 2013).
A theme found in almost all studies was personal growth and personal development and could relate to parents developing/gaining increased self-efficacy and/or self-esteem. Parental self-efficacy was found to have the strongest bearing on maternal positivity in mothers of children with intellectual disabilities (Jess et al., 2017). Having high self-efficacy enables parents to exercise control over their lives, a prerequisite for problem-focused coping, and plays a significant role in health behaviours as low self-efficacy is associated with depression, anxiety and helplessness, whereas conversely having high self-efficacy is related to psychological well-being (Bandura, 1993).
Reporting improved and strengthened relationships with others could lead to increased social support for the parent. In parents of children with developmental disabilities, both social support and positive reframing coping strategies have been found to be influential mechanisms through which optimism influences "benefit finding" (Slattery, McMahon, & Gallagher, 2017). Social support is reported to be the strongest and most frequently used strategy in high coping families which contain a child with intellectual disabilities (Taanila, Syrjälä, Kokkonen, & Järvelin, 2002). This support may provide parents with the opportunity for discussion and to make meaning of their situation (Lepore & Evans, 1996), directly enhance mental well-being and strengthen feelings of self-esteem and self-efficacy (Cohen & Wills, 1985). It is also suggested that interpersonal relationships may provide positive experiences that promote growth by bolstering positive affect (Cadell, Regehr, & Hemsworth, 2003).
Religion and spiritual beliefs have been found to provide an interpretative framework to understand, accept and view a child's disability in a more positive light (Durà-Vilà, Dein, & Hodes, 2010) and could also relate to increased social support gained from others, for example members of a church. In general studies, religiosity has been associated with benefit finding and strongly related to stress-related growth (Helgeson, Reynolds, & Tomich, 2006;Pargament, Smith, Koenig, & Perez, 1998;Park, Cohen, & Murch, 1996;Skinner, Correa, Skinner, & Bailey, 2001).
None of the studies in this review contained a comparison group of typically developing children with two studies acknowledging this limitation (9,15). Studies that have explored positive impacts in relation to parental ethnicity and which also included a control group of typically developing children concluded that parents of children with intellectual disability report the same types of positive perceptions of childrearing experiences as parents of typically developing children (Blacher & Baker, 2007). The parents in studies in this review described positive emotions such as joy, happiness, pride and love (Folkman & Moskowitz, 2004;Fredrickson, 2011), and when their child achieved something unexpected, they perceived this to be positive. However, similar themes have also been described as the joy of parenting a typically developing child (Brooks, 2013), and therefore, it is not possible to confirm whether the child being a source of happiness and fulfilment is an exclusive phenomenon of parenting a child with intellectual disabilities or whether it could be construed as common to the majority of parents describing their child and whether it is influenced by the sociocultural context (Blacher & Baker, 2007). This merits further investigation.
No studies included in this review reported post-traumatic growth (PTG) although one study explored benefit finding following adversity (8). Interestingly, Tedeschi and Calhoun (2013) who coined the term PTG initially used the terms "perceived benefits" and "pos- Similarly, no studies were included relating to positive reframing/positive reappraisal, despite this being a commonly used strategy used in benefit finding (Helgeson et al., 2006). However, these are coping strategies and the aim of the review was to explore what parents describe to be positive. However, it should be noted that statistically significant relationships have been found between positive reappraisal coping and PTG (Park et al., 1996;Urcuyo et al., 2005;Zoellner & Maercker, 2006). Similarly, meaning-making coping whereby a person gains greater control and is better able to look at events or a problem in a different way is reported to promote positive growth (Cadell et al., 2014).
All of the studies included were limited by their cross-sectional nature which provides a static view of parenting when caring is dynamic over the lifespan. Therefore, this review could provide only a limited understanding of any association between length of caring and reporting of positive aspects or benefit finding. The majority of studies included parents of children under the age of 19 years, and only one study contained a sample of only adult children (1).
In this and another study in which half of the participants were adult children (12), positive aspects were identified; however, these mostly related to undertaking caring duties for their adult child to a high standard with the concomitant appreciation by the child and other family members. Another study which included children aged 4-43 years described how looking after their child was a rewarding experience (15) but this was in contrast to parents of younger adults aged 16-21 years who considered the "absence of certain care demands" as a positive (11). The former studies are twenty years old, and it could be speculated that these parents are reporting positives as they wanted to keep their children at home and not be placed in a long stay institution as some of these parents may have been advised to do when their children were younger.
The children in the review were aged from birth to age 55 years, but evidence was scant if there were any differences in the type of positive aspects identified by parents and the child's age. Study 19 found no difference in the type of positive aspects identified by the parents across the child's age and when asked parents provided mixed responses as to whether they felt these changed over time.
It could be hypothesized that as the child ages, complex behaviours and medical conditions could worsen alongside the realization of the need for lifelong dependence which may affect the parent's ability to perceive positives. However, study 16 reported that families with older children (ages 15-17) were more likely to see positive aspects of their situation than those with younger children (6-8 years). In many studies relating to adversity, there is mixed evidence as to when any benefit finding occurs (Helgeson et al., 2006;Joseph & Linley, 2005;Picoraro, Womer, Kazak, & Feudtner, 2014;Zoellner & Maercker, 2006). It has also been argued that benefit finding is superficial and transient in nature (Tennen & Affleck, 2009)  longitudinal studies could aid understanding if parents are experiencing initial benefit finding (considered to be a positive reframing strategy), then PTG over time, or if they develop a repertoire of adaptive coping strategies as the child ages as it may possible that different constructs are being described by these parents. However, the use of all three constructs has been shown to increase eudaimonic mental well-being and therefore beneficial to these parents (Carver, Lechner, & Antoni, 2009;Joseph, Murphy, & Regel, 2012).
Only one study reported a significant negative correlation between the number of positive perceptions reported and the child having more severe intellectual disabilities (6), and therefore, this review was not able to confirm associations found in studies of adversity that greater levels of trauma (severity of intellectual disability) are associated with higher levels of benefit finding (Linley, 2004). Similarly, it was not possible to ascertain whether there was a curvilinear relationship with parents who report the most benefit finding experiencing a moderate rather than a low level of exposure to trauma (Helgeson et al., 2006).
The majority of studies were not initially theoretically grounded, but the findings of two studies (12,19) confirmed the validity of the transactional model of stress (TMS) (Lazarus & Folkman, 1987) concluding that many of the positive aspects/satisfactions described were linked to, or outcomes of, successful strategies of cognitive coping (meaning making). Positive reframing coping strategies were found to be a significant independent predictor for maternal positive perceptions by Hastings, Allen, McDermott, and Still (2002). This model was also considered to be a suitable theoretical framework to underpin the parents' positivity due to its emphasis on meaning-focused coping which includes positive reappraisal/ reframing coping strategies (19). Study 4 initially used an adapted version of the "working model for the study of families' positive perceptions" (Hastings & Taunt, 2002). However, their findings showed that this model had reduced explanatory powers and proposed that the findings instead provided evidence for "positive psychology" of which positive reframing and meaning making are two key aspects, along with positive relationships, positive emotions and pursuing mastery (Seligman & Csikszentmihalyi, 2000).
This was consistent with study 14 who concluded that parents were constructing meaning (Frankl, 1963). Another suggested support for the social constructivist theory of disability (13) (Oliver, 1990). Both benefit finding and PTG are underpinned by positive psychology, and further research which explores growth from this theoretical lens would increase understanding.
This review has highlighted several knowledge gaps which could aid work to support parents. Positive aspects are not consistently defined although are able to be identified. Clarification of this as a construct would lead to improved and consistent theoretical frameworks, methodologies and measurements being used and allow for more comprehensive comparisons of the findings to be made both within and across other carer groups. Identifying predictors of positive aspects (including those identified in this review) would be beneficial. This could guide professionals in providing support and identify early interventions including reframing strategies which may enhance parental positivity and improve mental well-being.

| LI M ITATI O N S
This review has revealed considerable heterogeneity of study designs and definitions which necessitated a rigorous and transparent narrative synthesis. Nevertheless, there are limitations.
A number of different terms were found to be used to describe positive aspects, and this difficulty of searching for positive aspects was also acknowledged in a systematic review of positive experiences BEIGHTON aNd WILLS of caregiving in stroke (Mackenzie & Greenwood, 2012). In addition, due to the wide range of terms used to describe an intellectual disability, despite rigorous searching, some studies might have been missed.
Similarly, some early publications may not have been found on searching as keywords were only uniformly adopted by journals after c. 2000.
There is far more evidence than is reported here that parents do have positive experiences. However, many studies were excluded due to the positive aspects being a dependent variable in quantitative papers. Another reason is that in some studies the children have disabilities or developmental disabilities (such as autism), but it was not stated that the children also have an intellectual disability therefore again were excluded.
Most of the studies recruited parents through service agencies or support groups who support people who have a learning disability. This is a common approach to research with this parent group as the low prevalence of intellectual disability in the population makes recruitment "notoriously difficult" and impractical to randomly sample from the population in order to obtain a sufficiently large sample (Gallagher, Phillips, Oliver, & Carroll, 2008:21). However, recruiting in this way can introduce selection bias because those parents who might experience stress would be more likely to attend support groups and some parents who do not attend might have differing perspectives. In addition, parents who may not be able to identify any positive aspects may not have volunteered to participate, limiting the generalisability of the findings.

| CON CLUS ION
There is an existing body of evidence about the positive aspects of