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Keywords:

  • glaucoma;
  • glaucoma treatment;
  • knowledge;
  • need for information;
  • expectations;
  • socioeconomic status

Abstract.

  1. Top of page
  2. Abstract.
  3. Introduction
  4. Materials and Methods
  5. Results
  6. Discussion
  7. Acknowledgement
  8. References

Purpose: To study the specific items for which socioeconomic differences in glaucoma patients' knowledge, need for information and expectations of treatments exist, with the aim of developing a patient education programme.

Methods: A total of 44 randomly selected ophthalmologists assigned 166 consecutive outpatient glaucoma patients to complete a questionnaire that had been systematically developed based on focus group interviews, suggestions from several experts and a pilot test. Topics included knowledge about glaucoma and its treatment, need for information and expectations of treatment. Educational level was used as a measure for socioeconomic status. Logistic regression analysis was conducted to adjust for age, sex and duration of glaucoma.

Results: After adjusting for age, sex and duration of glaucoma, knowledge of glaucoma and its treatment was found to be positively correlated with socioeconomic status. Items on knowledge with socioeconomic differences concerned risk factors, pathophysiology and consequences of glaucoma, as well as effects and adverse effects of treatments. The lowest socioeconomic group demonstrated more need for information on public assistance and practical aspects of glaucoma and more often expected that glaucoma damage could be repaired.

Conclusion: Important socioeconomic differences in knowledge, need for information and expectations of treatment exist in glaucoma patients. Patient education should focus on every glaucoma patient, but better information for the lower socioeconomic groups about specific items mentioned in this study might reduce the negative effects of low socioeconomic status on visual impairment.


Introduction

  1. Top of page
  2. Abstract.
  3. Introduction
  4. Materials and Methods
  5. Results
  6. Discussion
  7. Acknowledgement
  8. References

Despite equal financial access to health care services and relatively small differences in health care utilization between socioeconomic groups, socioeconomic inequalities in health still exist in western Europe and in the Netherlands (Mackenbach et al. 1997; Verkleij & Mackenbach 1998; Jansen & ten Dam 2002; Van der Lucht 2002). In the Netherlands, men and women with low levels of education enjoy 15 years less of good health and live, respectively, 4.9 and 2.6 years less than more highly educated men and women (Van der Lucht 2002). Compared with higher socioeconomic groups, people in lower socioeconomic groups report specific diseases and health complaints more often, have poorer general health and more often demonstrate unhealthy behaviour and unhealthy physical qualities (Stronks et al. 1998; Van der Lucht & Picavet 2003; Van Lenthe et al. 2004). People in lower socioeconomic groups use health care services more often; they have contact with the general practitioner more often, although they use specialist care and preventive services less frequently (Van der Meer et al. 1996; Jansen & ten Dam 2002).

It has been shown that, in other countries, socioeconomic differences in health and health care use also exist in ophthalmology. People from lower socioeconomic groups use eye care services less frequently, although the prevalence of visual impairment and blindness is higher in these groups (Srivastava & Verma 1978; Dana et al. 1990; Tielsch et al. 1991; Salive et al. 1992; Klein et al. 1994; Dandona et al. 1999, 2001b, 2002a, 2002b; Schaumberg et al. 2000; Dandona & Dandona 2001; Ho & Schwab 2001; Michon et al. 2002; Munoz et al. 2002). Socioeconomic differences are also observed in glaucoma patients. Lower socioeconomic status is associated with a diminished quality of life, late presentation of glaucoma and more visual field loss at the time of diagnosis, possibly increasing the risk of becoming blind (Sherwood et al. 1998; Fraser et al. 2001; Oliver et al. 2002). Other studies have pointed to a lack of knowledge concerning eye diseases and eye care in lower socioeconomic groups. In the general population, more years of formal education and higher socioeconomic status were positively correlated with knowledge and awareness of eye diseases, including glaucoma (Livingston et al. 1995; Attebo et al. 1997; Dandona et al. 2001a; Lau et al. 2002). In glaucoma patients, those with higher levels of education have more knowledge about glaucoma than patients with lower levels of education (Kim et al. 1997; Hoevenaars et al. 2005). Although studies show differences between socioeconomic groups in terms of knowledge of glaucoma, they do not describe the specific items for which such differences exist and the results do not give sufficient detailed information for the development of an educational programme to reduce the gap between high and low socioeconomic groups. We used an accurate and systematic process of item selection to identify in more detail the specific items for which a socioeconomic difference in knowledge exists. In addition, we investigated the socioeconomic differences in need for information and expectations of treatments. The present explorative study may therefore contribute to the development of a patient education programme.

Materials and Methods

  1. Top of page
  2. Abstract.
  3. Introduction
  4. Materials and Methods
  5. Results
  6. Discussion
  7. Acknowledgement
  8. References

Design and participants

A cross-sectional study with self-administered questionnaires was conducted. Sixty randomly selected ophthalmologists from the list of addresses of the Dutch Ophthalmological Society were asked to let four consecutive glaucoma patients fill in a questionnaire at the outpatient department. We aimed to achieve a maximum number of 240 patients. To increase the response rate, an incentive was included for both the ophthalmologists and patients. Moreover, all ophthalmologists were contacted by telephone after 2–3 weeks and by mail after 6–8 weeks to improve participation. No selection was made based on the duration of glaucoma or the type of glaucoma medication. If a patient refused or was unable to fill in the questionnaire, the ophthalmologists were asked to select the next consecutive patient and to number the patients according to the consecutive order.

Measurements

Focus group interviews were used to identify relevant items with respect to knowledge about glaucoma and its treatment, need for information and expectations with respect to treatment. Four focus group interviews with 22 patients from three general hospitals and one university hospital were carried out. None of the hospitals were private hospitals as there are only a few private hospitals for a limited number of diseases and interventions in the Netherlands. Nine of the patients were members of the Glaucoma Patient Society and were included in one focus group. Special emphasis was given to the inclusion of patients with a short duration of glaucoma as there are fewer of these patients. The duration of glaucoma was 1 year or less in eight patients. The initial routing questions for the focus group interview were developed by a health education specialist and were reviewed by two other health education specialists with experience in this field. The routing questions were adjusted after each focus group interview. The focus group interviews were recorded on tape and transcribed. This was used to select the items for the questionnaire. A concept of the questionnaire was submitted to a pharmacist with research experience in the use of glaucoma medication, an ophthalmologist specializing in glaucoma, two health education specialists with practical experience in patient education, a professor in patient education and the chairman of the Glaucoma Patient Society. A pilot test on 10 glaucoma patients was undertaken. Topics covered in the questionnaire were knowledge about glaucoma and its treatment, need for information and expectations of treatment. Patients were asked to answer 19 statements concerning knowledge of glaucoma and 18 statements concerning its treatment. The possible answers to these statements were ‘yes’, ‘no’ or ‘don’t know/no opinion'. Patients were asked to indicate whether they would like to receive much, some or no information on 22 topics concerning need for information. Expectations started with the sentence ‘I expect that my treatment of glaucoma …’ and concerned 16 items, which could be answered with ‘agree’, ‘neither agree nor disagree’, or ‘disagree’. Socioeconomic status was based on the highest educational level of patients. Groups were defined as low (primary education, lower technical education), middle (secondary education), and high (bachelor's degree, master's degree, other tertiary education). Age and duration of glaucoma were categorized (Table 1).

Table 1.  Mean values and differences to the lowest of the number of correct answers about glaucoma and its treatment related to socioeconomic status, gender, age and duration of glaucoma.
 No. of correct answers on glaucoma (n = 19)No. of correct answers on treatment of glaucoma (n = 18)
 Mean values (95% CI)Unadjusted difference* (95% CI)Adjusted difference* (95% CI)Mean values (95% CI)Unadjusted difference* (95% CI)Adjusted difference* (95% CI)
  • 95% CI = 95% confidence interval.

  • *

    (Not) adjusted for the other variables.

  • Reference for linear regression.

Socioeconomic group
Low8.4 (7.6–9.1)007.6 (6.9–8.2)00
Middle10.1 (9.2–10.9)1.7 (0.6–2.8)0.9 (−0.1–2.0)9.0 (8.1–9.8)1.4 (0.3–2.4)0.6 (−0.4–1.7)
High11.4 (10.6–12.2)3.0 (1.8–4.2)2.5 (1.3–3.7)9.8 (8.9–10.7)2.2 (1.1–3.3)1.8 (0.7–2.9)
Gender
Male9.7 (8.9–10.6)008.5 (7.8–9.2)00
Female9.7 (9.0–10.5)0 (−1.0–1.0)0.4 (−0.5–1.4)8.7 (8.0–9.3)0.2 (−0.8–1.1)0.6 (−0.3–1.5)
Age (years)
26–5411.6 (10.7–12.5)0010.4 (9.5–11.4)00
55–6410.5 (9.3–11.8)−1.1 (−2.5–0.3)−1.0 (−2.4–0.3)9.3 (8.2–10.4)−1.1 (−2.4–0.2)−1.3 (−2.6–0.03)
65–748.8 (8.0–9.7)−2.8 (−4.0− −1.5)−2.0 (−3.2− −0.7)7.6 (6.9–8.3)−2.9 (−4.0− −1.7)−2.3 (−3.5− −1.1)
≥ 758.3 (7.6–9.0)−3.3 (−4.6− −2.0)−2.5 (−3.9− −1.2)7.6 (6.8–8.5)−2.8 (−4.0− −1.5)−2.5 (−3.7− −1.2)
Duration (years)
< 28.9 (7.9–9.9)007.5 (6.6–8.3)00
2–510.0 (9.1–10.9)1.2 (−0.2–2.5)1.4 (0.2–2.7) 9.0 (8.1–9.9)1.5 (0.3–2.8)1.7 (0.6–2.9)
> 510.2 (9.4–10.9)1.3 (0.1–2.6)1.5 (0.4–2.6)9.2 (8.5–9.9)1.7 (0.6–2.9)1.8 (0.8–2.9)

Statistical analysis

Data were entered in a database by two typists independently of one another and were checked and corrected when needed. Missing answers for a question with ‘don’t know/no opinion' as an answer category were classified as ‘don’t know/no opinion'. In the statistical analysis, the numbers of correct answers were separately calculated for knowledge about glaucoma and treatment of glaucoma. Mean values and 95% confidence intervals for the number of correct answers were calculated for every socioeconomic group. Linear regression analysis was conducted to adjust for age, sex and duration of glaucoma. As it was not known if there was a linear relation between the number of correct answers and socioeconomic status, age and duration of glaucoma, dummy variables were used. This made it possible to show any non-linear relation.

Percentages of correct answers were also calculated per statement for each socioeconomic group. Logistic regression analysis was conducted to adjust the proportion of correct answers on knowledge for age, sex and duration of glaucoma. The percentage of patients who stated a need for information was calculated per topic and per socioeconomic group. To adjust for age, sex and duration of glaucoma, logistic regression analysis was also conducted on the percentages of patients who indicated a need for information. Socioeconomic differences in knowledge and need for information are expressed as odds ratios (OR) with the corresponding 95% confidence intervals for each of the statements and each of the socioeconomic groups, taking the high socioeconomic group as reference category (OR = 1). The percentage answering each of three categories of expectations were calculated per socioeconomic group. A chi-squared test was used to test for statistically significant differences.

Results

  1. Top of page
  2. Abstract.
  3. Introduction
  4. Materials and Methods
  5. Results
  6. Discussion
  7. Acknowledgement
  8. References

In all, 73% of the ophthalmologists responded (n = 44) and 166 patients participated. Thirty-four ophthalmologists returned four questionnaires, two returned five, five returned three, two sent two and one returned only one questionnaire. Based on reports from 30% of the participating ophthalmologists, it was calculated that 85% of the consecutive patients asked by the ophthalmologist participated. Reasons for not participating were cognitive dysfunction, language barriers and lack of time. The mean age of the patients was 65 years (standard deviation 13 years). Eighty-six men (52%) and 79 women (48%) participated. The gender of one subject was unknown. In 40 patients (24%) glaucoma had been diagnosed less than 2 years previously. Sixty-nine (42%) patients belonged to the low socioeconomic group, 53 (32%) to the middle socioeconomic group, and 43 (26%) to the high socioeconomic group. The data for one patient were missing.

The association between the socioeconomic status of glaucoma patients and their knowledge of glaucoma and its treatment is given in Tables 1, 2 and 3. Patients from the low socioeconomic group showed poorer results when compared with the middle and high socioeconomic groups (Table 1). Knowledge increased with longer duration of glaucoma and decreasing age. There was no difference between the sexes. The socioeconomic differences in knowledge remained present after adjusting for sex, age and duration of glaucoma.

Table 2.  Number of correct answers about glaucoma stratified to each socioeconomic group and results of multiple logistic regression analysis.
Statements about glaucomaLow SEC (n = 69)Middle SEC (n = 53)High SEC (n = 43)
 n (%) OR (95% CI)n (%) OR (95% CI)n (%) OR (95%CI)
  1. SEC = socioeconomic group.

  2. OR (95% CI) = odds ratio (95% confidence interval) for knowledge about glaucoma adjusted for age, sex and duration of glaucoma.

If the visual field is impaired, this can be repaired26 (38)29 (55)28 (65)
0.3 (0.1–0.8)0.6 (0.3–1.6)1
Young people more often have glaucoma than older people42 (61)36 (68)37 (86)
0.2 (0.1–0.72)0.2 (0.6–0.7)1
Glaucoma often causes impaired reading26 (38)23 (43)27 (63)
0.6 (0.2–1.7)0.4 (0.2–1.2)1
There is only one type of glaucoma18 (26)16 (30)22 (51)
0.3 (0.1–0.8)0.3 (0.1–0.8)1
Medicines other than eyedrops can influence the intraocular pressure20 (29)11 (21)22 (51)
0.4 (0.2–1.1)0.2 (0.1–0.5)1
Glaucoma affects the visual field46 (67)45 (85)38 (88)
0.3 (0.1–1.0)0.7 (0.2–2.3)1
The optic nerve is damaged in glaucoma16 (23)19 (36)19 (44)
0.4 (0.2–1.0)0.6 (0.3–1.5)1
It is possible to have glaucoma without knowing it53 (77)51 (96)42 (98)
0.1 (0.0–0.7)0.5 (0.0–5.6)1
Without treatment, glaucoma is a FAST progressing condition16 (23)10 (19)18 (42)
0.7 (0.3–2.0)0.4 (0.1–1.1)1
Nutrition influences glaucoma22 (32)27 (51)22 (51)
0.5 (0.2–1.3)0.9 (0.4–2.3)1
The chance of getting glaucoma is higher if a family member has glaucoma42 (61)42 (79)34 (79)
0.5 (0.2–1.4)0.7 (0.2–2.2)1
The intraocular pressure is increased if it exceeds 2533 (48)40 (76)28 (65)
0.5 (0.2–1.3)1.8 (0.7–4.5)1
The chance of getting glaucoma is higher if the intraocular pressure is increased57 (83)51 (96)41 (95)
0.1 (0.0–0.8)0.8 (0.1–6.5)1
A patient should always tell the ophthalmologist which other diseases (s)he has45 (65)38 (72)32 (74)
0.4 (0.2–1.2)0.8 (0.3–2.2)1
Glaucoma causes reduction of visual acuity45 (65)37 (70)31 (72)
0.7 (0.3–1.8)0.8 (0.3–2.0)1
African people have a higher chance of getting glaucoma2 (3)4 (8)3 (7)
0.6 (0.1–4.4)0.9 (0.2–5.4)1
Strong myopia or hypermetropia gives a higher chance of getting glaucoma5 (7)4 (8)4 (9)
0.6 (0.1–3.3)0.4 (0.1–2.3)1
The intraocular pressure is always increased in glaucoma10 (15)11 (21)7 (16)
1.0 (0.3–3.2)1.4 (0.5–4.3)1
A patient should always tell the ophthalmologist which other medicines (s)he is using55 (80)41 (77)35 (81)
0.8 (0.3–2.4)0.8 (0.3–2.2)1
Table 3.  Number of correct answers about the treatment of glaucoma stratified by socioeconomic group and results of multiple logistic regression analysis.
Statements about the treatment of glaucomaLow SEC (n = 69)Middle SEC (n = 53)High SEC (n = 43)
 n (%) OR (95% CI)n (%) OR (95% CI)n (%) OR (95%CI)
  1. SEC = socioeconomic group.

  2. OR (95% CI) = odds ratio (95% confidence interval) for knowledge about the treatment of glaucoma adjusted for age, sex and duration of glaucoma.

Early detection and treatment will NOT slow down the course of glaucoma19 (28)26 (49)27 (63)
0.3 (0.1–0.6)0.6 (0.2–1.4)1
Laser treatment or surgery for glaucoma can repair the damage caused by glaucoma15 (22)23 (43)21 (49)
0.4 (0.1–1.0)0.8 (0.3–2.1)1
Some eyedrops should not be used by cardiac patients or asthma patients23 (33)25 (47)25 (58)
0.3 (0.1–0.8)0.5 (0.2–1.3)1
Eyedrops can repair the damage caused by glaucoma39 (57)38 (72)35 (81)
0.4 (0.1–1.2)0.5 (0.2–1.4)1
A slower heart rate could be an adverse effect of eyedrops3 (4)10 (19)12 (28)
0.1 (0.0–0.6)0.6 (0.2–1.9)1
Dyspnoea could be an adverse effect of eyedrops5 (7)12 (23)12 (28)
0.2 (0.1–0.8)0.6 (0.2–1.8)1
Each treatment is equally good for everyone33 (48)29 (55)28 (65)
0.6 (0.3–1.5)0.6 (0.2–1.4)1
Stinging or burning of the eyes could be an adverse effect of eyedrops49 (71)45 (85)36 (84)
0.7 (0.2–2.0)1.0 (0.3–3.3)1
Eyedrops can be replaced by tablets22 (32)19 (36)19 (44)
0.7 (0.3–1.8)0.6 (0.2–1.4)1
The course of the disease can be slowed down by eyedrops58 (84)46 (87)40 (93)
0.4 (0.1–1.8)0.4 (0.1–1.5)1
The use of eyedrops is redundant after laser treatment or surgery for glaucoma24 (35)31 (59)19 (44)
0.7 (0.3–1.7)1.6 (0.7–3.7)1
A high intraocular pressure must always be treated1 (1)4 (8)4 (9)
0.5 (0.0–7.2)0.6 (0.1–3.9)1
Discoloration of the iris may be an adverse effect of eyedrops18 (26)19 (36)14 (33)
0.7 (0.3–1.9)1.1 (0.5–2.7)1
Blurred vision after dropping could be an adverse effect of eyedrops51 (74)40 (76)34 (79)
0.7 (0.3–2.0)0.7 (0.3–2.1)1
Even if the intraocular pressure is under control, the visual field has to be checked61 (88)45 (85)39 (91)
0.6 (0.1–2.9)0.4 (0.1–1.8)1
It is possible to lose vision completely as a result of laser treatment or surgery for glaucoma7 (10)2 (4)3 (7)
0.8 (0.2–4.5)0.5 (0.1–3.3)1
The pharmacy checks which medicines one is using47 (68)31 (59)27 (63)
1.2 (0.5–3.0)0.7 (0.3–1.7)1
Glaucoma can only be treated by lowering the intraocular pressure49 (71)30 (57)26 (61)
1.5 (0.6–3.8)0.8 (0.3–1.8)1

The items in Tables 2 and 3 represent the sequence of the statements with the largest difference in correct answers between the high and low socioeconomic groups. More detailed analyses revealed socioeconomic differences in knowledge in 13 of 37 statements in the questionnaire (Tables 2 and 3). Ten of these statements showed differences between the low and high socioeconomic groups. Two statements showed socioeconomic differences for the low and middle socioeconomic groups, compared with the high socioeconomic group. One item showed a difference between the middle and high socioeconomic groups. Items showing a strong association between socioeconomic status and knowledge concerned risk factors, pathophysiology and consequences of glaucoma, as well as effects and adverse effects of the treatment of glaucoma.

Socioeconomic differences in terms of need for information were apparent in six of 22 topics (Table 4). Five of these topics showed differences for the low and middle socioeconomic groups compared with the high socioeconomic group. One topic showed a difference between the low and high socioeconomic groups. The sequence of the topics in Table 4 is based on the highest difference in need for information between socioeconomic groups. Patients from the low socioeconomic group expressed more need for information, especially about use of eyedrops, social support and assistance, social securities, resources and rehabilitation possibilities and how to learn to cope with glaucoma (Table 4). Patients in the low socioeconomic group also differed from those in the other groups in their expectations of treatment (results not shown). They more often expected that their glaucoma damage could be repaired. A total of 35% of those in the low socioeconomic group agreed with this statement, compared with 26% and 12% of the middle and high socioeconomic groups, respectively (p = 0.004). In terms of significant worsening of vision, 73%, 94% and 88% of patients in the low, middle and high socioeconomic groups, respectively, expected that their vision would not deteriorate substantially (p = 0.012). The statement concerning the expectation that they could continue their activities of daily life easily was agreed with by 71%, 89% and 86% of the low, middle and high socioeconomic groups, respectively (p = 0.09). The statement declaring that the respondent could expect to visit the ophthalmologist less often was agreed with by 36%, 19% and 19% of the low, middle and high socioeconomic groups, respectively (p = 0.09).

Table 4.  Number of patients demonstrating a need for information, stratified to socioeconomic group and results of multiple logistic regression analysis.
TopicLow SEC (n = 69)Middle SEC (n = 53)High SEC (n = 43)
 n (%) OR (95% CI)n (%) OR (95% CI)n (%) OR (95%CI)
  1. SEC = socioeconomic group.

  2. OR (95% CI) = odds ratio (95% confidence interval) for need for information adjusted for age, sex and duration of glaucoma.

How to use and apply eyedrops38 (64)25 (49)14 (34)
6.0 (2.2–16.3)2.9 (1.1–7.3)1
Social support or assistance at home38 (61)31 (62)14 (34)
3.0 (1.2–7.7)2.9 (1.2–7.3)1
Resources or rehabilitation for the visually impaired45 (73)40 (80)22 (54)
3.2 (1.2–8.7)3.8 (0.4–10.7)1
Experiences of other glaucoma patients35 (58)36 (72)19 (46)
2.7 (1.0–7.3)3.5 (1.3–9.2)1
Social securities for visually impaired people42 (70)37 (73)20 (49)
2.8 (1.1–7.1)2.6 (1.0–6.6)1
Other diseases that influence glaucoma43 (73)47 (92)38 (95)
0.2 (0.0–1.2)0.7 (0.1–4.4)1
How to learn to cope with glaucoma49 (78)38 (78)24 (57)
3.4 (1.3–9.2)3.1 (1.1–8.3)1
Laser treatment and eye-surgery46 (73)46 (89)34 (81)
0.9 (0.3–2.8)2.1 (0.6–7.3)1
Possible results of treatments52 (83)50 (96)35 (85)
1.2 (0.3–5.0)3.8 (0.6–22.5)1
The present condition of your glaucoma53 (82)48 (94)37 (88)
0.7 (0.2–2.8)1.7 (0.4–8.4)1
The possible course and consequences of your glaucoma52 (85)48 (96)39 (93)
0.6 (0.1–3.2)1.5 (0.2–10.6)1
New developments concerning glaucoma and its treatment54 (87)50 (96)41 (98)
0.2 (0.0–2.0)0.5 (0.0–6.2)1
The cause of glaucoma51 (82)45 (87)37 (93)
0.6 (0.1–2.8)0.7 (0.2–3.4)1
Eyedrops50 (81)41 (80)29 (73)
2.7 (0.9–8.2)2.2 (0.7–6.6)1
Possible adverse effects of treatments53 (83)47 (90)35 (85)
1.1 (0.3–4.1)1.6 (0.4–6.9)1
The Glaucoma Patient Society35 (58)28 (55)25 (61)
1.3 (0.5–3.2)0.9 (0.4–2.3)1
Heredity of glaucoma48 (77)42 (82)35 (83)
1.1 (0.3–3.8)0.9 (0.3–3.1)1
Where to find good education material about glaucoma48 (77)42 (82)35 (83)
1.1 (0.4–3.5)1.1 (0.3–3.4)1
How to function better with glaucoma49 (79)38 (75)30 (73)
1.6 (0.6–4.4)1.1 (0.4–3.0)1
Work and glaucoma27 (48)27 (54)20 (50)
2.3 (0.8–6.3)1.9 (0.7–5.0)1
Social aspects of glaucoma37 (63)31 (62)27 (68)
0.8 (0.3–2.2)0.8 (0.3–2.2)1
Psychological aspects of glaucoma42 (69)33 (66)26 (65)
1.2 (0.5–3.1)1.0 (0.4–2.6)1

Discussion

  1. Top of page
  2. Abstract.
  3. Introduction
  4. Materials and Methods
  5. Results
  6. Discussion
  7. Acknowledgement
  8. References

The present study shows socioeconomic differences in glaucoma patients' knowledge about glaucoma and its treatment, even when differences in age, gender and duration of glaucoma are taken into account. The most and largest differences exist between the low and high socioeconomic groups, while the middle and high socioeconomic groups show rather small differences. Patients in the low socioeconomic group also have a need for information about other items, compared with those in the other groups, and have other expectations of their treatment. Concerning the need for information, great differences exist between the low and high socioeconomic groups, as well as between the middle and high socioeconomic groups.

An important advantage of this study is the development of the questionnaire, which was based on a systematic item selection through focus group interviews and consultation with several experts. The questionnaire was very extensive and contained important items with which to develop a new patient education programme. The questionnaire had good internal consistency; Cronbach's alpha was 0.83, ranging from 0.81 to 0.83 when items were deleted one at a time (data not shown).

The results were based on a nationwide sample of patients. The selection of patients might be a shortcoming of the study. It is difficult to assess case order. The high response rate of 85% was achieved because patients were asked to fill in the questionnaire at the outpatient department. It was impossible to control whether ophthalmologists asked four consecutive patients to fill in the questionnaire or whether they selected the patients. It is, however, hardly imaginable that all the ophthalmologists selected patients in a consistent manner, thus biasing the reported results. It is unknown whether patients who refused or were unable to fill in the questionnaire had a specific lower or higher level of knowledge. However, it is difficult to select patients otherwise. If patients were selected from one hospital or from the national Glaucoma Patient Society, bias would certainly have been introduced. In conclusion, although not perfect, the selection method was the best we could achieve to reduce selection bias.

This study confirms the results of other studies in which differences between socioeconomic groups in terms of knowledge were also observed (Kim et al. 1997; Hoevenaars et al. 2005).

It has been reported that glaucoma patients from lower socioeconomic groups have more severe visual field loss at the time of diagnosis, which might increase the risk of becoming blind (Fraser et al. 2001; Oliver et al. 2002). The results of the present study suggest that there might be a relationship between differences in knowledge, need for information and expectations, and this late presentation with glaucoma. For example, in our study, patients from the low socioeconomic group less often knew that the likelihood of getting glaucoma is higher if intraocular pressure is increased, that it is possible to have glaucoma without knowing it and that early detection and treatment will slow down the course of glaucoma. Because they are also less aware of the fact that a family predisposition is a risk factor for glaucoma, they do not encourage their family members to check for glaucoma, leading to more avoidable visual impairment in the lower socioeconomic group. This could also be one of the explanations for the fact that patients from lower socioeconomic groups use eye care services less often than patients from higher socioeconomic groups.

The quality of life for glaucoma patients is also worse in patients from low socioeconomic groups (Sherwood et al. 1998). This might be a result of more severe glaucoma at presentation, but may also be due to less effective treatment or more adverse effects of treatment. For example, patients in the low socioeconomic group less often knew that some eyedrops should not be used in patients with cardiac disease or asthma. They were also less aware of the symptoms that may indicate an adverse effect of the glaucoma medication. This might result in more unnecessary adverse effects in these groups and lower rates of compliance (Zimmerman & Zalta 1983). Moreover, patients in the low socioeconomic group more often expected that treatment could repair their glaucoma damage. This unrealistic expectation may lead to more dissatisfaction when patients from low socioeconomic groups receive treatment.

The socioeconomic groups did not differ much on items like ‘Strong myopia or hypermetropia gives a higher chance of getting glaucoma’ and ‘It is possible to lose vision completely as a result of laser treatment or surgery for glaucoma’. Only a few patients in each group knew the correct answers to these statements.

In general, the low socioeconomic group demonstrated greater need for information. Odberg et al. (2001) reported that patients aged less than 60 years missed twice as much information about their disease as older patients did. Younger patients especially wanted to know more about the causes of glaucoma and the risk of going blind. In the current study, patients in the low socioeconomic group more often expressed the need for information on the use and application of eyedrops, implying that their current use may possibly be less effective. The quality of life of low socioeconomic group patients with glaucoma may also be influenced by the lack of support to compensate the consequences of having glaucoma. When compared to the other socioeconomic groups, more of these patients expressed a need for information on social support or assistance at home, aids or rehabilitation facilities for the visually impaired, information on how to learn to cope with glaucoma and information on available social security benefits. If this information need is fulfilled, patients in lower socioeconomic groups might be able to deal with the consequences of their glaucoma better, thereby improving their quality of life. Patients in all socioeconomic groups expressed a roughly equivalent, but high, need for information on items such as ‘The Glaucoma Patient Society’, ‘Heredity of glaucoma’, ‘How to function better with glaucoma’ and ‘Psychological aspects of glaucoma’.

In conclusion, the current study shows important socioeconomic differences in knowledge, need for information and expectations of glaucoma patients. As the overlap in level of knowledge between socioeconomic groups is considerable, and the level of knowledge is low in every socioeconomic group, patient education should focus on every glaucoma patient. We suggest that better provision of information to patients in lower socioeconomic groups about the specific items mentioned above could reduce their higher risk of becoming blind, contribute to an earlier presentation of glaucoma, improve their quality of life, adjust their expectations, reduce the incidence of adverse effects and improve compliance. In this way, the socioeconomic differences in eye care utilization and prevalence of visual impairment in glaucoma patients might be reduced.

Acknowledgement

  1. Top of page
  2. Abstract.
  3. Introduction
  4. Materials and Methods
  5. Results
  6. Discussion
  7. Acknowledgement
  8. References

The authors thank the National Health Care Insurance Board, The Netherlands, for its financial support.

References

  1. Top of page
  2. Abstract.
  3. Introduction
  4. Materials and Methods
  5. Results
  6. Discussion
  7. Acknowledgement
  8. References