Development of competence scale for senior clinical nurses

Authors


Itsuko Akamine, Okinawa Prefectural College of Nursing, 1-24-1 Yogi, Naha, Okinawa 902-0076, Japan. Email: iakamine@okinawa-nurs.ac.jp

Abstract

Aim:  The aim of this study was to develop a new scale, the Competence Scale for Senior Clinical Nurses (CS-SCN), to assess and evaluate senior clinical nurses in hospitals, and to confirm the validity and reliability of the scale.

Method:  A cross-sectional questionnaire survey was undertaken at a hospital in Japan, using an anonymous self-administered questionnaire administered to clinical nurses (n = 374). A useable sample of 218 was achieved, which was used in the analysis. Statistical analysis examined exploratory/confirmatory factor analysis, internal consistency, and construct validity.

Results:  A five factor solution with 22 items was extracted for nursing competence in senior clinical nurses, which was the interpretable questionnaire. In the confirmatory factor analysis, the indices of fitness supported these results. Cronbach's alpha coefficient was 0.93 for the total score and varied between 0.63 and 0.90 in the five factors. Five factors emerged from an oblique factor analysis, with a cumulative variance of 66.7%: “role accomplishment”; “self-management”; “research”; “practice and coordination”; and “work implementation”. The five factors had only a moderate correlation (0.30–0.77, P < 0.001) with each other, which indicated construct validity.

Conclusion:  The CS-SCN, a concise scale to measure and evaluate the competence of senior clinical nurses, was developed. Results suggest initial support for the new instrument as a measure of competence of senior clinical nurses, but it must be further refined, tested, and evaluated. Both the validity and reliability of the scale were verified. Future studies using the CS-SCN might lead to improvement in the competence of senior clinical nurses.

INTRODUCTION

Competence in nursing can be defined as having the knowledge, skills, and values that lead to best nursing practices and the highest possible level of job performance (Blevins, 2001). Competence is a dynamic state influenced by experience and education (Benner, 1984). Beginning in the early 1980s, many nursing boards began to explore the issue of competence for graduating nurses in the USA (Tilley, 2008). Nursing competence is now seen as central to patient-care outcomes, and its importance reaches far beyond the domain of nursing regulation and licensing (Cowin et al., 2008). Indeed, competence in nursing has a direct influence on the health and safety of all patients, and the safety of patients receiving medical care is clearly associated with the competence of healthcare providers (Axley, 2008).

Competence is a topic of great interest to educators and administrators in practice disciplines, particularly health care disciplines such as nursing (Tilley, 2008). Competence is an ongoing process of initial development, maintenance of knowledge and skills, educational consultation, remediation, and redevelopment, and is only part of the process of maintaining a high-quality workforce (Whelan, 2006). The acquisition of competence in nursing specialties is a process that continues over the long term; it does not conclude with basic education.

With advances in medicine and diversification of patient needs, more diverse and complex nursing care is also demanded. In Japan, Certified Nurse Specialist and Certified Nurse systems were established to develop nurses with a high level of competence, and training and certification mechanisms for these systems have been established (Japanese Nursing Association, 2009). Nonetheless, most nurses in clinical settings are generalists. The basic abilities required at completion of basic nursing education and during the first year after graduation have been identified and evaluated (JNA, 2005). However, little progress has been made regarding efforts to identify, evaluate, and develop the competencies required for senior clinical nurses in Japan. In hospitals in Japan, continuing ongoing education programs for clinical nursing competence generally continue until the third year after graduation, and they are planned and implemented according to years after graduation. Learning for senior clinical nurses with more than 5 years of nursing experience is not covered by such programs, and so it is mostly left to the awareness and responsibility of the individual (Hirai, 2003). The use of continuing ongoing nursing education is important for cultivating appropriate and effective nursing competence; however, evaluating the results and effectiveness of continuing ongoing nursing education is even more important. It is also important to measure and evaluate nursing competence. The main roles of senior clinical nurses are to provide management, leadership, and education, which are important for ensuring that their hospitals provide quality care. Senior clinical nurses require many skills to fulfill these roles. Therefore, a scale for measuring and evaluating their nursing competence was necessary.

The published work contains several reports on scales to measure nursing competence in Japan and other countries (Garland, 1996; Meretoja, Isoaho, & Leino-Kilpi, 2004; Saeki, Izumi, Uza, & Takasaki, 2003; Sato, Ushida, Naito, Deguchi, & Tosa, 2007; Schwirian, 1978; Tosa et al., 2002). The Six Dimension Scale of Nursing Performance (Six-D Scale), developed by Schwirian (1978) to measure nursing competence, consists of six categories. Some studies have used the Six-D Scale, which was translated and modified for use in Japan (Matsuyama, Yamaguchi, & Komiyama, 1997; Nanke et al., 2005; Oba, 2009; Saita & Asoshina, 2010). However, the Six-D Scale was developed to evaluate the performance of the schools' graduates (Schwirian, 1978). Similarly, the Nurse Competence Scale (NCS), which was developed by Meretoja et al. (2004), evaluates core competence skills for nursing practice. These scales were not designed to measure the competence of senior clinical nurses. Benner (1984) evaluated the nursing practice from novice to expert, but did not use a specific measurement scale. Thus, it is necessary to develop a new scale for measurement of senior clinical nurses.

In this study, senior clinical nurses were defined as those with 5 or more years of clinical experience. According to Benner (1984), proficient performance can usually be found in nurses who have worked with similar patient populations for approximately 3–5 years.

The aim of this study was to develop a new scale, the Competence Scale for Senior Clinical Nurses (CS-SCN), to assess and evaluate senior clinical nurses in a hospital, and to confirm the validity and reliability of the scale.

METHODS

This study adopted a three stage process to develop a nursing competence scale for senior clinical nurses (Fig. 1). In stage 1, abilities demanded of senior clinical nurses were identified. In stage 2, preparation of the item pool, and in stage 3, a cross-sectional questionnaire survey and factor analysis (exploratory/confirmatory) was undertaken at a hospital in Japan.

Figure 1.

Flow chart of study participants. CS-SCN: Competence Scale for Senior Clinical Nurses.

Stage 1: Identification of abilities demanded

In August 2007, with the aim of developing a program to cultivate competence in senior clinical nurses, an eight member research team was established consisting of two nursing department administrators, two head nurses, and one assistant head nurse in a municipal hospital, and three university researchers (faculty). The team discussed the status of senior clinical nurses, staff development, and continuing ongoing nursing education at a municipal hospital. The research team recognized the necessity and importance of measuring and identifying competence of senior clinical nurses in developing the training program and creating an evaluation system.

The abilities demanded of senior clinical nurses were discussed by the research group formed in August 2007. The discussions in each meeting of the research group were tape recorded, and verbatim transcriptions were made. The discussion related to competence in senior clinical nurses was extracted from these transcripts, and content analysis was performed. One hundred and forty-nine recorded items were extracted from the transcripts and classified into 14 categories of ability. These classifications and category names were examined within the research team. The discussions were held five times from August 2007 to January 2008.

Stage 2: Preparation of the item pool

Based on the 14 nursing competence categories identified in stage 1, question items were created to measure competence in senior clinical nurses. There were 29 question items across the ability categories. The scores were calculated by using a 4 point Likert scale (1, “not sufficient”; 2, “slightly insufficient”; 3, “slightly sufficient”; 4, “sufficient”).

To investigate the content validity and face validity of the question items, the prepared questions were checked by one head nurse and two assistant head nurses who were not members of the research team. To examine the face validity, these experts checked whether the question content measured competence of senior clinical nurses, whether the question was appropriate, and whether the wording of the question made it difficult for subjects to respond.

Stage 3: Questionnaire survey and factor analysis

Survey

Survey content.  In addition to the 29 items thought to indicate nursing competence of senior clinical nurses investigated in stage 2, the survey contained questions on sex, age, years of clinical experience, and nursing unit.

Participants.  The initial subjects were 374 nurses working at a municipal hospital in Japan. A questionnaire survey was conducted with these nurses, and a usable sample of 218 was achieved (response rate, 58.3%). Statistical analysis examined exploratory/confirmatory factor analysis with 172 nurses with more than 5 years of experience (Fig. 1).

Data collection.  A cross-sectional questionnaire survey was undertaken at a hospital in Japan, using an anonymous self-administered questionnaire administered to clinical nurses (n = 374) between April and May 2008.

Data analysis

Statistical analysis examined exploratory/confirmatory factor analyses, internal consistency, and construct validity. SPSS ver. 17.0J (SPSS Japan, Tokyo, Japan), and IBM SPSS Amos for Japan ver. 19.0 (IBM SPSS Japan, Tokyo, Japan) were used. The significance level was set at P < 0.05 (two-tailed).

Item analysis.  For the 29 question items on nursing competence of senior clinical nurses, descriptive statistics were performed, and ceiling (mean + standard deviation [SD]) and floor effects (mean − SD) were calculated. The range of each item's score was 1–4, and the scale floor effect and ceiling effect were mean −1 SD < 1 and mean +1 SD > 4, respectively (Oshio, 2008).

In addition, item-total (I-T) correlation analysis was conducted, inter-item correlation coefficients were calculated, and item analysis was performed. When a pair of items correlates very highly, one of the items is considered redundant (Juniper, Guyatt, Streiner, & King, 1997). Six pairs of items had correlation coefficients of more than 0.70 and were considered redundant (Idvall, Hamrin, & Unosson, 2002). In each pair, the item with the worst properties was eliminated. The usual rule of thumb is that an item should correlate with the total score above 0.2 (Streiner & Norman, 2008).

Factor analysis.  Exploratory factor analysis is used to reduce the number of items and develop scales in the preliminary field test stage of the study (Hobart, Riazi, Lamping, Fitzpatrick, & Thompson, 2004). One item in the preliminary factor analysis with a factor loading of less than 0.3 was deleted. As the first step in developing a new measurement scale, exploratory factor analysis was conducted for the 22 competence question items. In selecting factors, a principal factor method was used, oblique factor rotation was done with the direct oblimin method, and the factor structure was clarified. When conducting the exploratory factor analysis, the Kaiser–Meyer–Olkin (KMO) measurement and Bartlett's sphericity test were used to confirm the validity of the samples. The KMO measurement shows the validity of observed variables dealt with in the factor analysis; if a KMO measurement of 0.80 or 0.90 is achieved, this supports the use of factor analysis. Bartlett's sphericity test is used to evaluate whether a correlation matrix is suitable for factor analysis by testing the hypothesis that the matrix is an identity matrix, and if low probability is obtained and the hypothesis of an identity matrix is rejected, this supports the use of the factor analysis (Munro, 2005). The number of factors was determined through the following criteria: the interpretability of each factor; eigenvalues of more than 1.0; and scree plot characteristics.

A confirmatory factor analysis (CFA) was conducted to check the construct validity and to confirm the dimensionality of these five factors.

Examination of reliability.  Reliability was investigated with the use of Cronbach's alpha coefficient to demonstrate the internal consistency (Streiner & Norman, 2008) of the nursing competence scale.

Examination of validity.  Construct validity was confirmed from the factor structure extracted with factor analysis. A known-group technique was also used to investigate construct validity. In this procedure, groups that are expected to differ on the critical attribute because of some known characteristic are administered the instrument (Polit & Hungler, 1999). To determine the discriminative power of the scale of nursing competence in senior clinical nurses, the participants were divided into two groups, those with 4 years or less of clinical experience and those with 5 years or more of experience. Student's t-test was performed to compare these two groups in terms of mean value of the overall nursing competence scale score and each subscale score. Age and years of clinical experience are thought to be the most important variables affecting nursing competence in senior clinical nurses. The correlation between age and years of clinical experience was r = 0.94, so the years of clinical experience was used.

Ethical considerations

The protocol of this study was approved by the research ethics committee of Okinawa Prefectural College of Nursing. In addition, administrative approval was obtained from the subject's hospital.

RESULTS

Participant demographics (for questionnaire survey)

Responses were obtained from 252 subjects who consented to participate in the study. After excluding incomplete responses, valid responses from 218 people (response rate, 58.3%) were used in the analysis.

Women accounted for the majority (85.8%) of the 218 analysis subjects (Table 1). By age group, the greatest proportion was aged 30–39 years (48.6%). Clinical experience was 4 years or less in 21.1% and 5 years or more in 78.9%.

Table 1. Characteristics of participants (n = 218)
CharacteristicsN%
Sex  
 Male31(14.2)
 Female187(85.8)
Age (years)  
 22–2950(22.9)
 30–39106(48.6)
 40–4941(18.8)
 50–5919(8.7)
 Unknown2(0.9)
Clinical work experience in nursing (years)
 Junior (n = 46)  
  ≤446(21.1)
 Senior (n = 172)  
  5–958(26.6)
  10–1974(33.9)
  20–2934(15.6)
  ≥306(2.8)
Nursing unit  
 Internal medicine69(31.7)
 Surgery36(16.5)
 Mixed6(2.8)
 Pediatrics15(6.9)
 Obstetrics and gynecology13(6.0)
 Outpatient11(5.0)
 Operating room18(8.3)
 Dialysis14(6.4)
 Intensive care unit15(6.9)
 Emergency room14(6.4)
 Other7(3.2)

Item analysis

In the item analysis of the 22 question items on nursing competence (Table 2), the range of mean (SD) for each item was 2.1 (0.8) to 3.2 (0.6). No ceiling effect or floor effect was seen for any item. Moderate correlations were seen between all items in the inter-item correlation. In the I-T correlation analysis, the correlation coefficient was in the range r = 0.42−0.81, and the score for each item was related to total score. From the above, it was determined that no items could be deleted at that stage.

Table 2. Question items and item analysis of the Competence Scale for Senior Clinical Nurses (n = 172)
Items Score, mean ± standard deviationItem–total correlation
Q1Can identify problems in one's nursing unit, work to resolve them, and implement and evaluate them2.4 ± 0.60.71
Q2Can understand the standpoint of guidance and training recipients, and make modifications2.5 ± 0.70.72
Q3Has legal knowledge of nursing practices, and can respond appropriately to social changes related to medical safety with interest in medical information2.4 ± 0.70.67
Q4Can identify one's career development goals2.4 ± 0.70.67
Q5Can recognize one's role in the organization, and can execute work tasks2.8 ± 0.60.72
Q6Can display leadership within one's department, coordinate work among the team, and give guidance and advice2.4 ± 0.80.78
Q7Can work to improve manuals of nursing standards and procedures2.6 ± 0.70.74
Q8Can make judgments on one's own and perform tasks without instructions from superiors2.8 ± 0.60.42
Q9Can balance work and home/private life2.8 ± 0.80.45
Q10Can participate in training voluntarily and acquire and retain the latest nursing knowledge and skills2.3 ± 0.80.43
Q11Can conduct nursing studies to improve the quality of nursing, and present research findings2.1 ± 0.80.61
Q12Can comprehensively understand and assess the patient and family2.5 ± 0.70.65
Q13Can coordinate between the nursing team and other medical teams to provide appropriate treatment and care2.5 ± 0.80.72
Q14Can provide high-level nursing care based on evidence in one's area of specialty2.4 ± 0.70.70
Q15Can coordinate between superiors, colleagues, and junior nurses from a neutral standpoint2.5 ± 0.70.68
Q16Can guide and train students and trainees2.5 ± 0.70.81
Q17Can respond swiftly to unexpected occurrences (can provide information, contacts, and consultation)2.9 ± 0.70.65
Q18Can predict crises that will affect patients and implement safety control with consideration of medical and workplace environments2.8 ± 0.60.70
Q19Can confirm with the doctor when there is some doubt as to his or her instructions3.2 ± 0.60.55
Q20Can listen to patients' complaints or wishes and respond/cope appropriately2.9 ± 0.60.68
Q21Can manage materials (e.g. supplies, drugs, medical devices)2.8 ± 0.70.57
Q22Can smoothly exchange opinions regarding nursing tasks with other staff3.0 ± 0.70.67

Examination of factor structure

An exploratory factor analysis was performed for the 22 items (Table 3). Prior to the factor analysis, the results of the KMO measurement and Bartlett's sphericity test, which indicates the validity of factor analysis samples, showed that all samples met the statistical criteria (KMO, 0.916; Bartlett's sphericity test, P < 0.001).

Table 3. Exploratory factor analysis of Competence Scale for Senior Clinical Nurses (n = 172)
Factor/itemFactor loading
Factor 1Factor 2Factor 3Factor 4Factor 5
  1. Values in bold indicate the highest loading. Cronbach's alpha for the total score was 0.93.

Factor 1: Role accomplishment (α = 0.90)
 Q1Can identify problems in one's nursing unit, work to resolve them, and implement and evaluate them 0.78 −0.010.050.000.06
 Q2Can understand the standpoint of guidance and training recipients, and make modifications 0.65 0.17−0.010.20−0.10
 Q3Has legal knowledge of nursing practices, and can respond appropriately to social changes related to medical safety with interest in medical information 0.53 −0.030.190.040.14
 Q4Can identify one's career development goals 0.53 0.110.170.090.00
 Q5Can recognize one's role in the organization and can execute work tasks 0.50 0.13−0.160.090.31
 Q6Can display leadership within one's their department, coordinate work among the team, and give guidance and advice 0.46 −0.010.100.300.13
 Q7Can work to improve manuals of nursing standards and procedures 0.42 −0.080.110.170.30
Factor 2: Self-management (α = 0.77)
 Q8Can cope with stress from various interpersonal relations0.07 0.90 0.00−0.12−0.03
 Q9Can balance work and home/private life−0.03 0.66 0.140.020.01
Factor 3: Research (α = 0.63)
 Q10Can participate in training voluntarily and acquire and retain the latest nursing knowledge and skills0.020.15 0.64 0.000.01
 Q11Can conduct nursing studies to improve the quality of nursing, and present research findings0.260.01 0.48 0.18−0.02
Factor 4: Practice and coordination (α = 0.86)
 Q12Can comprehensively understand and assess the patient and family−0.03−0.100.15 0.71 0.06
 Q13Can coordinate between the nursing team and other medical teams to provide appropriate treatment and care0.190.03−0.06 0.68 −0.01
 Q14Can provide high-level nursing care based on evidence in one's their area of specialty−0.03−0.020.12 0.66 0.13
 Q15Can coordinate between superiors, colleagues, and junior nurses from a neutral standpoint0.290.10−0.16 0.56 −0.04
 Q16Can guide and train students and trainees0.250.100.17 0.33 0.24
Factor 5: Work implementation (α = 0.83)
 Q17Can respond swiftly to unexpected occurrences (can provide information, contacts, and consultation)0.06−0.04−0.030.04 0.78
 Q18Can predict crises that will affect patients and implement safety control with consideration of medical and workplace environments0.13−0.040.140.01 0.69
 Q19Can confirm with the doctor when there is some doubt as to his or her instructions−0.090.23−0.030.17 0.46
 Q20Can listen to patients' complaints or wishes and respond/cope appropriately−0.060.190.100.32 0.39
 Q21Can manage materials (e.g. supplies, drugs, medical devices)0.35−0.020.02−0.05 0.38
 Q22Can smoothly exchange opinions regarding nursing tasks with other staff0.020.30−0.130.34 0.34
Rotation sums of squared loadings9.161.230.970.600.59
Proportion of variance (%)43.567.316.494.734.63
Cumulative proportion of variance (%)43.5650.8657.3562.0866.71

A principal method was used in estimating the factor loading in the exploratory factor analysis, and oblique rotation was used for factor rotation by direct oblimin method. As a result, all items had factor loading ≥0.3, no items were deleted, and 22 items and five factors were extracted. The first five factors each had an eigenvalue greater than 1.0. Variance accounted for by these factors (as rounded) was 43.6%, 7.3%, 6.5%, 4.7%, and 4.6%, respectively. Together, these factors accounted for 66.7% of the overall variance between items. It was determined that the five factor model was the most interpretable.

The five extracted factors were named based on their content: factor 1, “role accomplishment” (seven items); factor 2, “self-management” (two items); factor 3, “research” (two items); factor 4, “practice and coordination” (five items); factor 5, “work implementation” (six items) (Table 3). The five factors were defined as follows.

Factor 1

Abilities of role accomplishment for senior clinical nurses include identifying problems in one's nursing unit, working to resolve, implement, and evaluate these problems, having legal knowledge of nursing practice, responding appropriately to social changes related to medical safety, recognizing one's role in the organization, and executing work tasks, and displaying leadership.

Factor 2

Abilities of self-management include coping with stress from various interpersonal relations and balancing work and home/private life.

Factor 3

Abilities of research involve acquiring and retaining the latest nursing knowledge and skills, conducting nursing studies to improve the quality of nursing, and presenting research findings.

Factor 4

Abilities of practice and coordination include comprehensively understanding and assessing the patient and family, coordinating between the nursing team and other medical teams to provide appropriate care, providing high-level nursing care based on evidence, and guiding and training students and trainees.

Factor 5

Abilities of work implementation include responding swiftly to unexpected occurrences, predicting crises that will affect patients, and implementing safety control measures with consideration of the medical and workplace environment.

A CFA was conducted to check the construct validity and to confirm the dimensionality of these five factors. Figure 2 shows the result of CFA. This solution indicated sufficient fitness to the factor structure. The fit indices for this model were moderately acceptable (χ2[d.f.] = 403.031 [204]; χ2/d.f. = 1.976; P < 0.001; goodness of fit index, 0.829; adjusted goodness fit index, 0.788; comparative fit index, 0.898; root mean square error of approximation, 0.076).

Figure 2.

Confirmatory factor analysis of the Competence Scale for Senior Clinical Nurses. CS-SCN: Competence Scale for Senior Clinical Nurses. χ2 (d.f.) = 403.031 (204); χ2/d.f. = 1.976; goodness of fit index, 0.829; adjusted goodness of fit index, 0.788; comparative fit index, 0.898; root mean square error of approximation, 0.076.

Examination of scale reliability

Internal consistency according to Cronbach's alpha coefficient was used to investigate the reliability of the scale. Cronbach's alpha coefficient for the total score was 0.93. The coefficients for each factor were 0.90, 0.77, 0.63, 0.86, and 0.83 for factors 1, 2, 3, 4, and 5, respectively (Table 3).

Examination of scale validity

In the factor analysis, five factors were extracted: “role accomplishment”; “self-management”; “research”; “practice and coordination”; and “work implementation”. The relationship of the five factors and question items described above is shown in Table 3. In addition, the correlations between the domain scores of the CS-SCN were r = 0.30−0.76 (P < 0.01) (Table 4).

Table 4. Correlations between the domain scores of the Competence Scale for Senior Clinical Nurses, and means and SD of each factor score (n = 172)
 Factor 1Factor 2Factor 3Factor 4Factor 5Score
MeanSD
  1. Pearson's correlations: ***P < 0.001. SD, standard deviation.

Factor 1: Role accomplishment1.0017.473.75
Factor 2: Self-management0.31***1.005.401.43
Factor 3: Research0.50***0.30***1.004.341.30
Factor 4: Practice and coordination0.76***0.30***0.46***1.0012.412.88
Factor 5: Work implementation0.70***0.35***0.38***0.72***1.0017.582.85

As a known-groups technique, subjects were divided into those with 4 years or less of experience and those with 5 years or more of experience, and these groups were compared with Student's t-test of mean values for each factor and the total score of the CS-SCN. Significant differences were found between the groups for each factor (factor 1, P < 0.001; factor 2, P = 0.005; factor 3, P = 0.001; factor 4, P < 0.001; and factor 5, P < 0.001) and for total score (P < 0.001) (Table 5).

Table 5. Comparison of clinical junior and senior nurses' factor scores
AbilityJunior (n = 46)Senior (n = 172)Student's t-test
MeanSDMeanSDDifference in mean values95% CI P-value
  1. CI, confidence interval; SD, standard deviation.

Factor 1: Role accomplishment14.413.9217.473.753.051.81−4.29<0.001
Factor 2: Self-management4.721.495.401.430.680.21–1.150.005
Factor 3: Research3.631.124.341.300.710.30−1.130.001
Factor 4: Practice and coordination9.593.3612.412.882.821.84−3.80<0.001
Factor 5: Work implementation14.464.2117.582.853.121.80−4.44<0.001
Total score46.8012.3757.199.9210.386.95−13.81<0.001

DISCUSSION

Given the lack of evaluation scales for competence of senior clinical nurses in Japan, the development of the CS-SCN is important. This tool has only 22 items, so respondents have little difficulty in completing it. The CS-SCN would be useful for senior clinical nurses, as well as researchers, to measure the competence of senior clinical nurses, to evaluate interventions and continuing education for senior clinical nurses, and to conduct research. It would also be useful for managers to improve and evaluate the competence of senior clinical nurses. The CS-SCN might be appropriate in clinical settings in Japan.

Although the study sample was limited to a hospital, the results of this study can be generalized for measuring of senior clinical nurses in any hospital in Japan, because identification of the competence was conducted by experienced clinicians and researchers and the item pool was confirmed by other expert clinicians. Consequently, a more accurate understanding of the competence of senior clinical nurses will facilitate the development of effective continuing nursing education programs for senior clinical nurses.

Items on a scale should be moderately correlated with each other, and each should correlate with the total scale score (Streiner & Norman, 2008). In the results of the present study, moderate correlations were seen between all items in the inter-item correlation and the score for each item was related to the total score. The internal consistency of the scale was thus confirmed.

Factor analysis is an essential tool in scale development (DeVellis, 2003). Researchers are beginning to use a complex modeling procedure referred to as CFA for making factor comparisons (Polit, 1996). The factor structure for all items was confirmed, which indicated good indices of fitness for the CFA. The concise structure might make the scale more understandable for nurses and researchers and easy to use in a clinical setting. The factor analysis revealed a five factor structure, which seems appropriate to grasp the characteristics of competence of senior clinical nurses. These procedures ensured the face and content validity of the CS-SCN.

Five factors constituting nursing competence in senior clinical nurses were extracted in the factor analysis: “role accomplishment”; “self-management”; “research”; “practice and coordination”; and “work implementation”.

Factor 1, “role accomplishment”, is the ability to take care of the elements that are most important in the role of a senior clinical nurse, and these tasks require extremely high competence in nursing. Munro (2005) stated that the first factor was a generalized factor upon which all variables load. These abilities are obtained by accumulating nursing experience; more than 5 years of experience is thought to be needed to obtain these skills. Senior clinical nurses need to demonstrate not only personal efforts but also organizational understanding and support. These skills include the ability to grasp and analyze issues in one's department, discover measures for resolution of these issues, and advance efforts to change the current situation. Improving or developing nursing care and raising the level of ability to solve problems in one's department, such as by improving the working environment, are expected to lead directly and indirectly to the provision of higher quality care to patients.

Senior clinical nurses are expected to serve as instructors or leaders (Shimada, 1999) while also providing nursing care autonomously. To fulfill that role, they need to acquire and update knowledge and skills corresponding to the changing medical environment and roles; continuing development of nursing competence is essential for senior clinical nurses (Oyamada, 2009).

Moreover, senior clinical nurses, in addition to providing nursing care for patients, have important roles in vitalizing not only the nursing department but the entire hospital organization, such as by coordinating between superiors, department nurses, and other staff.

Factor 2, “self-management”, is the ability to cope with stress from various interpersonal relations and to balance work and home/private life. Many senior clinical nurses are at a stage in life where they have various responsibilities, such as childrearing, housework, and caring for parents, in addition to their work as a nurse. Thus, in addition to job stress, they are in a situation in which they must deal with these other issues while performing their work. The work/family conflict also has a large influence on the physical and mental health of nurses (Takeuchi & Yamazaki, 2010). Outstanding self-management ability is demanded of senior clinical nurses, and they must maintain their health and try to manage their lives in order to provide care to patients. At the same time, they also need organizational support, apart from their own efforts, to realize their self-management ability. Such support includes coordination of working hours, consideration of the work system, and utilization of other systems. This factor correlated with other factors; therefore, self-management ability was considered to support the maintenance and improvement of other factor abilities.

Factor 3, “research”, is the ability to use evidence-based nursing in nursing practice. Research is recognized as an essential basis for nursing knowledge and practice development, and there is considerable agreement that nurses do not use research as often as they could (Retsas & Nolan, 1999). Nurses vary in their ability to appraise research quality and lack individual authority to implement research findings (Flemming, 2007). In the present results, this factor was significantly correlated with other factors. This suggests that improving research abilities may be important in improving competency of senior clinical nurses. To provide high-level nursing care based on evidence-based nursing, senior clinical nurses have to get the latest nursing knowledge and skill from the research.

Factor 4, “practice and coordination”, is an important element for clinical nurses in providing direct care. Senior clinical nurses are developing skills in evidence-based practice (Gerrish, Ashworth, Lacey, & Bailey, 2008), and they need to provide high-level nursing care based on evidence in their specialty area. They also need to coordinate between the nursing team and other medical teams to provide appropriate treatment and care. Senior clinical nurses are thought to have the ability to accurately monitor patients' conditions, to provide high-quality care, and to coordinate efficiently and effectively with patients and their families, doctors, and co-medical staff. Education and experience are important components in a nurse's ability to promote high-quality care (Hallin & Danielson, 2007), and nurses with little experience learn high-quality care for patients with support from experienced nurses.

Factor 5, “work implementation”, is the ability to grasp the work adequately, and respond swiftly. Senior clinical nurses have to respond swiftly to unexpected occurrences. In addition, they also have to predict crises that will effect patients and implement safety control with consideration of the medical and workplace environment. To improve patient safety, nurses must have the ability to recognize changes in patient condition, perform independent nursing interventions, anticipate orders, and prioritize (Fero, Witsberger, Wesmiller, Zullo, & Hoffman, 2009).

These five factors indicate abilities that should clearly be developed by senior clinical nurses. As a middle correlation was seen between the five factors, the factors are thought to improve complementarily through various senior nursing practices. It is important to develop each competency, and appropriately evaluate and improve one's own nursing competence. The indicators developed in this study might be used to make appropriate evaluations of the competence of senior clinical nurses.

Reliability and validity of the scale

Cronbach's alpha coefficient is a measure of internal consistency reliability. A Cronbach's alpha coefficient higher than 0.7 is considered to indicate high reliability (Munro, 2005). The Cronbach's alpha coefficient of the overall CS-SCN was 0.93, indicating reliability. The Cronbach's α coefficient for each factor was more than 0.6, so the CS-SCN was thought to be reliable.

Validity is commonly defined as the extent to which a test measures what it is intended to measure (McDowell & Newell, 1996). By construct validity, five factors were extracted in the exploratory factor analysis. These factors accounted for 66.7% of the overall variance between items, which is considered sufficient. Based on the criterion that the minimum eigenvalue (for rotated factors) was 1, the first five factors were rotated. Eigenvalues often after are the key criteria for determining the number of factors to be rotated (Munro, 2005). Moreover, the individual question items making up each factor showed factor loading of 0.3 or more, which were the highest values compared with factor loading shown by other factors. Loadings with an absolute value of 0.30 or more are considered sufficiently large to attach meaning to them (Polit, 1996). This solution indicated sufficient fitness to the factor structure by CFA. The validity and reliability of the CS-SCN were confirmed. The construct validity was therefore thought to be assured for the scale.

A comparison was made of the mean values for factors and the scale overall for two groups – those with 4 years or less experience and those with 5 years or more experience – and significant differences were seen in all cases. On the whole, it would be anticipated that the two group differences would be reflected in the mean scores (Polit & Hungler, 1999). Thus, the CS-SCN was considered to have discriminative power. Discriminability refers to the ability to differentiate the construct being measured from other similar constructs (Polit & Hungler, 1999).

From the above, the CS-SCN was thought to have uniform reliability and validity, and discriminative power.

Use of the CS-SCN in clinical settings

The aim of nurse competence assessment is to measure whether nurses achieve professional standards (Cowin et al., 2008). With the self-evaluation used in the CS-SCN, it is possible to review one's own nursing competence and gain a more objective understanding of one's nursing competency level. In addition, nurses can understand the abilities that need improvement based on their score on the CS-SCN; this may lead them to improve their nursing competency by strengthening those abilities through continuing education and practice. Continuing nursing education is the key to expanding competency in the knowledge and skills needed to provide patient-centered care. Using the CS-SCN, clinical settings can also assess the competence of senior clinical nurses in their nursing departments before and after continuing education inside and outside of the clinical setting such as training to raise nursing competence. It may be more prudent for staff development educators and nurse managers in practice settings to collaborate in identifying essential competencies specific to the setting, and developing or selecting appropriate methods of measurement of these competencies (Waddell, 2001).

Competence is something that can be acquired by learning that involves looking back on one's own experience and incorporating the experiences of others (Furukawa, 2010). It is also a process that enables an organization to reliably provide high-quality care to clients or patients. Integration of knowledge, attitudes, and skills is also decisive in ensuring nursing competence in a hospital (Whelan, 2006). Consequently, when considering how to improve the nursing competence of each nurse, there are limits to what can be achieved with the efforts of the individual nurse alone. Support from the hospital organization is also needed. Enhanced support for areas of competence that need to be strengthened in senior clinical nurses identified by the CS-SCN might be valuable from the perspective of cost-effectiveness. Continuing nursing education provided in a group setting can effectively improve the nursing competence of several nurses for a fixed cost.

Study limitations

This study has several limitations. Establishment of the criterion-related validity of the CS-SCN should have been attempted; however, this item could not be confirmed. In the future, it will be necessary to confirm criterion-related validity using the Six-D Scale (Schwirian, 1978) and NCS (Meretoja et al., 2004). Investigating the validity of the scale using criteria other than years of experience in future research should strengthen the scale validity. Furthermore, it is necessary to investigate the validity of the scale using criteria other than years of clinical experience.

This study involved only one hospital, and there may be limits to the general use of the tool developed. In the future, it will be necessary to increase the number of clinical settings and amount of data collected, and to further investigate the reliability and validity of the scale for general adoption.

CONCLUSION

The CS-SCN, a concise scale to measure and evaluate the competence of senior clinical nurses, was developed. Results suggest initial support for the new instrument as a measure of competence of senior clinical nurses, but it must be further refined, tested, and evaluated. Both the validity and reliability of the scale were verified. Future studies using the CS-SCN might lead to the improvement of the competence of senior clinical nurses.

ACKNOWLEDGMENT

This study was supported by a Grant-in-Aid for Scientific Research (no.20592510 and no.23593182) from the Japan Society for the Promotion of Science.

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