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- Materials and Methods
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.
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- Materials and Methods
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.
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- Materials and Methods
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 glaucoma||Low SEC (n = 69)||Middle SEC (n = 53)||High SEC (n = 43)|
| ||n (%) OR (95% CI)||n (%) OR (95% CI)||n (%) OR (95%CI)|
|If the visual field is impaired, this can be repaired||26 (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 people||42 (61)||36 (68)||37 (86)|
|0.2 (0.1–0.72)||0.2 (0.6–0.7)||1|
|Glaucoma often causes impaired reading||26 (38)||23 (43)||27 (63)|
|0.6 (0.2–1.7)||0.4 (0.2–1.2)||1|
|There is only one type of glaucoma||18 (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 pressure||20 (29)||11 (21)||22 (51)|
|0.4 (0.2–1.1)||0.2 (0.1–0.5)||1|
|Glaucoma affects the visual field||46 (67)||45 (85)||38 (88)|
|0.3 (0.1–1.0)||0.7 (0.2–2.3)||1|
|The optic nerve is damaged in glaucoma||16 (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 it||53 (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 condition||16 (23)||10 (19)||18 (42)|
|0.7 (0.3–2.0)||0.4 (0.1–1.1)||1|
|Nutrition influences glaucoma||22 (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 glaucoma||42 (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 25||33 (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 increased||57 (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 has||45 (65)||38 (72)||32 (74)|
|0.4 (0.2–1.2)||0.8 (0.3–2.2)||1|
|Glaucoma causes reduction of visual acuity||45 (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 glaucoma||2 (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 glaucoma||5 (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 glaucoma||10 (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 using||55 (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 glaucoma||Low SEC (n = 69)||Middle SEC (n = 53)||High SEC (n = 43)|
| ||n (%) OR (95% CI)||n (%) OR (95% CI)||n (%) OR (95%CI)|
|Early detection and treatment will NOT slow down the course of glaucoma||19 (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 glaucoma||15 (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 patients||23 (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 glaucoma||39 (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 eyedrops||3 (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 eyedrops||5 (7)||12 (23)||12 (28)|
|0.2 (0.1–0.8)||0.6 (0.2–1.8)||1|
|Each treatment is equally good for everyone||33 (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 eyedrops||49 (71)||45 (85)||36 (84)|
|0.7 (0.2–2.0)||1.0 (0.3–3.3)||1|
|Eyedrops can be replaced by tablets||22 (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 eyedrops||58 (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 glaucoma||24 (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 treated||1 (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 eyedrops||18 (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 eyedrops||51 (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 checked||61 (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 glaucoma||7 (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 using||47 (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 pressure||49 (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.
|Topic||Low SEC (n = 69)||Middle SEC (n = 53)||High SEC (n = 43)|
| ||n (%) OR (95% CI)||n (%) OR (95% CI)||n (%) OR (95%CI)|
|How to use and apply eyedrops||38 (64)||25 (49)||14 (34)|
|6.0 (2.2–16.3)||2.9 (1.1–7.3)||1|
|Social support or assistance at home||38 (61)||31 (62)||14 (34)|
|3.0 (1.2–7.7)||2.9 (1.2–7.3)||1|
|Resources or rehabilitation for the visually impaired||45 (73)||40 (80)||22 (54)|
|3.2 (1.2–8.7)||3.8 (0.4–10.7)||1|
|Experiences of other glaucoma patients||35 (58)||36 (72)||19 (46)|
|2.7 (1.0–7.3)||3.5 (1.3–9.2)||1|
|Social securities for visually impaired people||42 (70)||37 (73)||20 (49)|
|2.8 (1.1–7.1)||2.6 (1.0–6.6)||1|
|Other diseases that influence glaucoma||43 (73)||47 (92)||38 (95)|
|0.2 (0.0–1.2)||0.7 (0.1–4.4)||1|
|How to learn to cope with glaucoma||49 (78)||38 (78)||24 (57)|
|3.4 (1.3–9.2)||3.1 (1.1–8.3)||1|
|Laser treatment and eye-surgery||46 (73)||46 (89)||34 (81)|
|0.9 (0.3–2.8)||2.1 (0.6–7.3)||1|
|Possible results of treatments||52 (83)||50 (96)||35 (85)|
|1.2 (0.3–5.0)||3.8 (0.6–22.5)||1|
|The present condition of your glaucoma||53 (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 glaucoma||52 (85)||48 (96)||39 (93)|
|0.6 (0.1–3.2)||1.5 (0.2–10.6)||1|
|New developments concerning glaucoma and its treatment||54 (87)||50 (96)||41 (98)|
|0.2 (0.0–2.0)||0.5 (0.0–6.2)||1|
|The cause of glaucoma||51 (82)||45 (87)||37 (93)|
|0.6 (0.1–2.8)||0.7 (0.2–3.4)||1|
|Eyedrops||50 (81)||41 (80)||29 (73)|
|2.7 (0.9–8.2)||2.2 (0.7–6.6)||1|
|Possible adverse effects of treatments||53 (83)||47 (90)||35 (85)|
|1.1 (0.3–4.1)||1.6 (0.4–6.9)||1|
|The Glaucoma Patient Society||35 (58)||28 (55)||25 (61)|
|1.3 (0.5–3.2)||0.9 (0.4–2.3)||1|
|Heredity of glaucoma||48 (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 glaucoma||48 (77)||42 (82)||35 (83)|
|1.1 (0.4–3.5)||1.1 (0.3–3.4)||1|
|How to function better with glaucoma||49 (79)||38 (75)||30 (73)|
|1.6 (0.6–4.4)||1.1 (0.4–3.0)||1|
|Work and glaucoma||27 (48)||27 (54)||20 (50)|
|2.3 (0.8–6.3)||1.9 (0.7–5.0)||1|
|Social aspects of glaucoma||37 (63)||31 (62)||27 (68)|
|0.8 (0.3–2.2)||0.8 (0.3–2.2)||1|
|Psychological aspects of glaucoma||42 (69)||33 (66)||26 (65)|
|1.2 (0.5–3.1)||1.0 (0.4–2.6)||1|
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- Materials and Methods
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.
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.