The relationship between visual acuity and functioning and well-being among diabetics

Visual impairment and multimorbidity in a representative sample of the Spanish population

BACKGROUND

In the context of population aging, visual impairment has emerged as a growing concern in public health. However, there is a need for further research into the relationship between visual impairment and chronic medical conditions in the elderly. The aim of our study was to examine the relationship between visual impairment and three main types of co-morbidity: chronic physical conditions (both at an independent and additive level), mental health and cognitive functioning.

METHODS

Data were collected from the COURAGE in Europe project, a cross-sectional study. A total of 4,583 participants from Spain were included. Diagnosis of chronic medical conditions included self-reported medical diagnosis and symptomatic algorithms. Depression and anxiety were assessed using CIDI algorithms. Visual assessment included objective distance/near visual acuity and subjective visual performance. Descriptive analyses included the whole sample (n = 4,583). Statistical analyses included participants aged over 50 years (n = 3,625; mean age = 66.45 years) since they have a significant prevalence of chronic conditions and visual impairment. Crude and adjusted binary logistic regressions were performed to identify independent associations between visual impairment and chronic medical conditions, physical multimorbidity and mental conditions. Covariates included age, gender, marital status, education level, employment status and urbanicity.

RESULTS

The number of chronic physical conditions was found to be associated with poorer results in both distance and near visual acuity [OR 1.75 (CI 1.38-2.23); OR 1.69 (CI 1.27-2.24)]. At an independent level, arthritis, stroke and diabetes were associated with poorer distance visual acuity results after adjusting for covariates [OR 1.79 (CI 1.46-2.21); OR 1.59 (CI 1.05-2.42); OR 1.27 (1.01-1.60)]. Only stroke was associated with near visual impairment [OR 3.01 (CI 1.86-4.87)]. With regard to mental health, poor subjective visual acuity was associated with depression [OR 1.61 (CI 1.14-2.27); OR 1.48 (CI 1.03-2.13)]. Both objective and subjective poor distance and near visual acuity were associated with worse cognitive functioning.

CONCLUSIONS

Arthritis, stroke and the co-occurrence of various chronic physical diseases are associated with higher prevalence of visual impairment. Visual impairment is associated with higher prevalence of depression and poorer cognitive function results. There is a need to implement patient-centered care involving special visual assessment in these cases.

Ten-year change in vision-related quality of life in type 1 diabetes: Wisconsin epidemiologic study of diabetic retinopathy

PURPOSE

To investigate changes of vision-related quality of life during a 10-year period in a population with type 1 diabetes.

DESIGN

Prospective cohort study.

PARTICIPANTS

Individuals who had their diabetes diagnosed before 30 years of age were considered to have type 1 diabetes (N = 1210). Those who participated in both 14-year (1995-1996) and 25-year (2005-2007) follow-up examinations were included in the current analysis (N = 471).

METHODS

Vision-related quality of life was measured with the National Eye Institute Visual Function Questionnaire (NEI-VFQ-25).

MAIN OUTCOME MEASURES

Changes in vision-related quality of life scores.

RESULTS

Loss of 3 lines in the Early Treatment Diabetic Retinopathy Study (ETDRS) chart was the most important factor related to negative changes in the NEI-VFQ-25 scores in our study after controlling for confounders. Most important changes were observed in subscales, such as general vision (-6.46 points), mental health (-10.19 points), role difficulty (-6.90 points), and driving (-10.43 points). Unemployment and the development of long-term complications, such as nephropathy, were also associated with negative changes in some NEI-VFQ-25 subscale scores. However, changes in diabetic retinopathy status were not related to changes in any subscale after 10 years.

CONCLUSIONS

Change in visual acuity was the most important factor associated with changes in vision-related quality of life scores in individuals with type 1 diabetes during a 10-year period. Our findings support the necessity of close follow-up of individuals with type 1 diabetes to avoid development of long-term complications and vision loss to improve quality of life.

Critical evaluation of the use of research tools in evaluating quality of life for people with schizophrenia

Schizophrenia may lead to impairments in many aspects of life, including physical, cognitive, and role functioning. The subjective quality of life of people with schizophrenia has been shown to be lower than in the general population and appropriate patient-assessed health outcome measures are necessary to capture the distress and disability experienced by people living with a serious mental illness. Although psychiatry has been slow to become involved in quality of life measurement, the use of quality of life instruments has now been recognized as a means of evaluating the outcome of care interventions, in terms of symptoms and functioning. This paper evaluates the effectiveness of two widely used instruments: The Medical Outcomes Study Short Form Health Survey (SF-36) and The Lancashire Quality of Life Profile (LQoLP) in terms of reliability and validity in measuring the quality of life of people with schizophrenia. The LQoLP appeared to be best suited for evaluation of care programmes, whereas the SF-36 was more appropriate for medical trials, comparisons between patient groups, and assessment of the direct consequences of treatment on health and function. Subjective quality of life should, however, be considered to be distinct from clinical status and quality of life assessment should include the broadest range of indicators, to reflect the holistic ethos of mental health nursing.

Assessing the impact of visual acuity on quality of life in individuals with type 2 diabetes using the short form-36

OBJECTIVE

We sought to ascertain quality-of-life measures and utility values associated with visual acuity in type 2 diabetes.

RESEARCH DESIGN AND METHODS

The Medical Outcome Study Short Form with 36 items (SF-36) was administered to 4,051 individuals with type 2 diabetes who were enrolled in the Lipids in Diabetes Study, and their best attainable vision was determined using an Early Treatment of Diabetic Retinopathy Study chart, expressed as a LogMAR score. Eight domain scores and a utility value representing an overall quality-of-life score were calculated using predefined algorithms. The associations between quality of life measured and best-eye visual acuity were assessed graphically and by regression analysis.

RESULTS

All eight SF-36 domain scores were negatively associated with reduced visual acuity. The impact of lower levels of visual acuity ranged from a decline of 1.3 units for a 0.1-LogMAR increase for physical functioning and 0.6 units in mental health. Regression analysis indicated a negative association (P < 0.001) between utility and reduced visual acuity after controlling for sex, BMI, smoking status, and history of diabetes complications. Patients whose LogMAR scores equated to legally blind had, on average, 0.054 (95% CI 0.034-0.074) lower utility compared with patients with normal visual acuity.

CONCLUSIONS

Reduced visual acuity is negatively associated with quality of life. The utility scores estimated here should inform studies quantifying the burden of diabetes and those evaluating potential therapies for treating or preventing diabetic eye diseases.

Research Agenda-Setting Program for Geriatric Ophthalmology

The healthcare needs of an aging population of "baby boomers" (persons born between 1946 and 1964) will disproportionately affect ophthalmology. To meet this emerging need, the American Geriatrics Society and the John A. Hartford Foundation developed a research agenda-setting process for geriatric ophthalmology. A systematic literature search was performed using Medline from the years 1990 to 2000. The literature review (168 papers) was performed to determine the current state of information regarding selected issues in geriatric ophthalmology. A needs assessment for each of the identified topics was performed, gaps in the existing knowledge base were identified, and key questions for future research were proposed. A research agenda-setting process for geriatric ophthalmology might provide a structural framework for future research efforts in the field.

Development of a Questionnaire to Assess Subjective Vision Score in Myopes Seeking Refractive Surgery

PURPOSE

To assess vision in patients with myopia and myopic astigmatism before and after refractive surgery.

METHODS

A prospective controlled study of visual quality amongst myopes and astigmatic myopes. Focus groups, ophthalmic surgeons, and questionnaire experts devised a Subjective Vision Questionnaire (SVQ), modified after a pilot trial. Participants were administered the SVQ before clinical evaluation. Items answered by over 95%, with factor loadings > 0.55 were included. Test-retest reliability was assessed by repeat testing. Factor analysis identified groups of questions measuring particular dimensions of data.

RESULTS

Sixty-seven items were answered by 128 patients and reduced to 24 items in a final questionnaire. Factor analysis identified six types of questions within the questionnaire, the most important of which was related to driving.

CONCLUSION

The simplicity, low cost, and psychometric properties of the Subjective Vision Questionnaire support its use clinically and in research.

Quality of life in patients with malignant choroidal melanoma after radiotherapy

BACKGROUND

Patient-orientated endpoints have attracted little attention in patients with malignant choroidal melanoma. This study was conducted to explore the long-term effects of malignant choroidal melanoma and radiotherapy on QOL by means of a differentiated and modular QOL approach, including global QOL, social support, and mental health, in comparison with sociodemographically matched healthy controls.

METHODS

A random sample of 100 outpatients treated by radiotherapy were asked by mail to take part in a psychodiagnostic study [instruments: Short-Form 36 Health-Survey (SF-36), Symptom Checklist-90-Revised, German Social Support Questionnaire]. The same instruments were applied to a healthy control group, which was matched to patients with regard to age, gender, and vocational situation.

RESULTS

93 patients (average age 61.2 years) responded at an average of 5.5 years (+/-3.7) after diagnosis. Visual acuity in the affected eye decreased considerably from diagnosis (0.49+/-0.30) to participation in the study (0.09+/-0.21). Compared with healthy controls, patients reported on average statistically significantly lower global QOL (SF-36), whereas social support and mental distress did not differ. Frequencies of clinically relevant mental distress were significantly higher in patients than in controls (35.5% vs. 16.1%). Mental distress was associated with poorer visual acuity, but not with the extent of loss of visual acuity or number of follow-up treatments.

CONCLUSION

Patients with choroidal melanoma suffer from low long-term global QOL, and every third patient suffers from relevant mental distress. Regular screening for mental distress should be implemented along with psychological counseling. Additional follow-up treatment does not seem to induce mental distress.

Evaluation of equity in diabetes health care in relation to African and Caribbean ethnicity

OBJECTIVE

Many US studies have shown that ethnic minority groups have less access to health care. We evaluated whether black African and black Caribbean people with diabetes in the UK gain access to diabetes health care on an equitable basis compared with white people.

DESIGN

Cross-sectional questionnaire survey set in 29 general practices in south London. Main measures were self-reported morbidity, SF-36 scores and utilisation of health care. Analyses of utilisation variables were adjusted for age, sex, ethnic group, duration of diabetes, and socio-economic and health status.

RESULTS

There were 1,899 respondents (64%) from 2,983 individuals registered with diabetes. These included 799 white, 522 black Caribbean, 163 black African and 415 other subjects with type 2 diabetes. After adjusting for need, black Caribbeans reported higher utilisation of health care than white subjects for four of nine utilisation variables, and black Africans for two. For the remaining variables utilisation was equivalent in different ethnic groups. Black Caribbean subjects were more likely to be treated for hypertension if hypertensive (odds ratio 1.84, 95% CI 1.05 to 3.22), to use blood or urine self-monitoring (1.40, 1.04 to 1.88) and to have attended a diabetes nurse (1.34, 1.04 to 1.74) or dietician (1.49, 1.19 to 1.86). Black Africans were more likely to have attended a dietician (2.15, 1.40 to 3.29) or an ophthalmologist (1.72, 1.10 to 2.70) in the past year.

CONCLUSION

There was no evidence from this study that black African or black Caribbean subjects had less access to diabetes health care in relation to need.

Development and validation of the Diabetic Foot Ulcer Scale-short form (DFS-SF)

BACKGROUND

The Diabetic Foot Ulcer Scale (DFS) provides comprehensive measurement of the impact of diabetic foot ulcers on patients' QOL through self-administration of 64 items comprising 15 subscales.

OBJECTIVE

To develop and evaluate a short form of the DFS (DFS-SF) to reduce patient burden and the number of outcome measures, and to improve sensitivity to change in clinical condition.

METHODS

The DFS-SF was created through the analysis of data from a double-blind, placebo-controlled, randomised trial of the efficacy and safety of becaplermin (recombinant human platelet-derived growth factor BB) in the treatment of chronic, full-thickness, neuropathic, diabetic foot ulcers. Using these data, items demonstrating poor psychometric properties were eliminated. Exploratory factor analyses were then conducted to develop a new, more parsimonious scaling algorithm that optimised the internal consistency of the new subscales. Finally, data from two additional clinical trials were used to assess replicability of the DFS-SF subscale structure.

RESULTS

The DFS-SF contains a total of 29 items comprising six subscales. The results of both confirmatory and exploratory factor analyses provided support for the scaling algorithm. The DFS-SF subscales showed good internal consistency, reliability and construct validity, and demonstrated sensitivity to ulcer healing.

CONCLUSIONS

The results of this investigation indicate that the DFS-SF has good psychometric properties and replicability.

Validity of the SF-12 quality of life instrument in patients with retinal diseases

OBJECTIVE

To investigate the construct validity and reliability of the SF-12 with the SF-36 composite scores in patients with retinal diseases.

DESIGN

Cross-sectional study.

PARTICIPANTS

One thousand eighty-one patients with retinal disease presenting for care at a tertiary referral university-based retina practice.

METHODS

Each patient completed the SF-36 before his or her initial ocular examination. The SF-12 is based on a subset of 12 items from the SF-36.

MAIN OUTCOME MEASURES

Physical Composite Score (PCS) and Mental Composite Score (MCS) as determined by the SF-36 and SF-12.

RESULTS

Eight hundred thirty-nine (78%) of the participants had scorable PCS and MCS scores on the SF-12. No significant differences were found between the SF-36 and SF-12 for the PCS and MCS overall and stratified by the four most frequently occurring disease categories (all P > 0.20). There were statistically significant differences across the disease categories in the mean PCS scores (P < 0.001) on the SF-36 and SF-12 and the MCS score on the SF-36 (P = 0.04). The SF-12 PCS and MCS scores were highly correlated with similar indicators (composite scores and subscales) on the SF-36.

CONCLUSIONS

The SF-12 is a valid measure of general health status for ophthalmic research, as long as differences in mental composite scores do not need to be demonstrated between different ocular disease groups. The benefit of reduced administration time makes the SF-12 a recommended general quality-of-life outcomes tool.

Assessment of vision-related function in patients with age-related macular degeneration

OBJECTIVE

To investigate the validity of the visual function index (VF-14) in assessing visual function in patients with age-related macular degeneration (AMD).

DESIGN

Prospective noncomparative observational case series.

PARTICIPANTS

One hundred fifty-nine consecutive patients attending a sole practitioner's academic retina-only clinic from May 1998 through August 1998 and from May 1999 through August 1999.

MAIN OUTCOME MEASURES

Correlations were calculated between the VF-14 scores and the medical outcomes study 36-item short form (SF-36), weighted comorbidity scale, visual acuity and clinical AMD severity (stage), and vision self-assessment scales. Documentation of the severity of macular degeneration was performed by a sole examiner.

RESULTS

There was a moderately strong correlation between visual acuity and trouble with vision (r = 0.51), satisfaction with vision (r = -0.50), and overall quality of vision (r = -0.56). A strong correlation was noted between VF-14 score and patients' self-rating of amount of trouble with vision (r = -0.67), satisfaction with vision (r = 0.62), and overall quality of vision (r = 0.67). In comparison, correlations between SF-36 score and patients' self-rating of amount of trouble with vision, satisfaction with vision, and overall quality of vision ranged from r = 0.37 to r = -0.40. Linear regression analysis for the overall study population indicated that AMD severity was not an independently significant predictor of VF-14 score after adjusting for visual acuity. However, among patients with 20/20 vision in the better eye, AMD severity was an independently significant predictor of VF-14 score after adjusting for visual acuity in the worse eye.

CONCLUSIONS

The VF-14 exhibits a considerable degree of validity as a measure of functional impairment in patients with AMD. Age-related macular degeneration severity was an independently significant predictor of VF-14 score in the group of patients with 20/20 vision in the better eye, but this did not hold true for the overall study population. Age-related macular degeneration is associated with substantial impairment in reported visual function.

Utilisation of private care by public primary care clinic attenders with diabetes: relationship to health status and social factors

Private health care provision is important in most middle-income countries but factors influencing the demand for private care have not been well defined. This paper evaluated the relationships of health status and socio-economic variables with utilisation of private care by public primary care clinic attenders. The sample included 2117 randomly selected subjects with clinical diabetes attending 35 government health centres in Trinidad and Tobago. Measures included attendance at a private doctor, the type 2 Diabetes Symptom Checklist, the SF36 questionnaire, and indicators of socio-economic status. Of the sample, 1256 (59%) reported attending a private doctor, 577 (27%) attended a private doctor for diabetes, and 378 (18%) attended a private doctor regularly. Attendance at a private doctor was associated with lower SF36 scores. The odds ratio for a 10 unit increase in SF36 physical component score was 0.81, 95% confidence interval 0.72-0.91. After adjusting for demographic and social factors the relative odds were 0.89, 0.80 to 1.00. After allowing for differences in health status, the relative odds of attending for private care for those without a pipe borne water supply in the home, compared with those with water in the home, were 0.77, 0.63-0.94. Those living alone were less likely to attend a private doctor than those living with their children and partner (odds ratio 0.60, 0.43-0.83). Among people attending public clinics, the decision to utilise private care is sensitive to health status. After adjusting for health status, there was evidence for horizontal inequity in access to private care in relation to household amenities and composition.

Acquired esotropia: subjective and objective outcomes

PURPOSE

The measurement of outcomes of pediatric therapy will be increasingly important to third-party payers as they allocate health care resources. We undertook this study to assess the effectiveness of treatment of acquired esotropia, as measured subjectively by parents and objectively by examination.

METHODS

A chart review was used to gather objective clinical data from all patients presenting between 1994 and 1995 with esotropia after their first birthday. Parents' impressions of the quality and impact of treatment were tabulated by using a telephone questionnaire.

RESULTS

Of 48 patients studied (mean age, 3.8 years; 44 months' follow-up), the 26 with amblyopia were effectively treated in 81% of cases. Mean esotropic angles decreased, with glasses and/or surgery, from 33.1 to 4.9 PD at distance and from 40.0 to 11.4 PD at near. The average estimated cost of care was 547 dollars per patient per year. Parents considered treatment "extremely important" to their child's future happiness and success in 90% of cases.

CONCLUSION

Our experience has shown that treatment of acquired esotropia in childhood, while relatively inexpensive, is highly effective, both objectively and subjectively.

Measuring quality in pediatric ophthalmology

Pediatric ophthalmologists should respond to quality expectations inherent in all disciplines of medicine. The specialists must be able to collect data to document and prove the quality of their work if it anticipates continued reimbursement for services. Quality of medical practice is assessed by outcomes research, which is different from clinical research. All specialists are systemically measuring individual and group outcomes across the spectrum of American health care systems. Pediatric ophthalmologists, both in private practice and at academic centers, must concentrate their research efforts on the assessment of cost, quality, utilization, and patient-centered health-related quality of life for the most common pathologies in pediatric ophthalmology practice.

Prevalence of self-rated visual impairment among adults with diabetes

OBJECTIVES

This study estimated the prevalence of self-rated visual impairment among US adults with diabetes and identified correlates of such impairment.

METHODS

Self-reported data from the 1995 Behavioral Risk Factor Surveillance System survey of adults 18 years and older with diabetes were analyzed. Correlates of visual impairment were examined by multiple logistic regression analysis.

RESULTS

The prevalence of self-rated visual impairment was 24.8% (95% confidence interval [CI] = 22.3%, 27.3%). Among insulin users, multivariable-adjusted odds ratios were 4.9 (95% CI = 2.6, 9.2) for those who had not completed high school and 1.8 (95% CI = 1.0, 2.8) for those who had completed high school compared with those with higher levels of education. Comparable estimates of odds ratios for nonusers of insulin were 2.2 (95% CI = 1.4, 3.4) and 1.3 (95% CI = 0.9, 2.0), respectively. Among nonusers, the adjusted odds for minority adults were 2.4 (95% CI = 1.0, 3.7) times the odds for non-Hispanic Whites.

CONCLUSIONS

By these data, 1.6 million US adults with diabetes reported having some degree of visual impairment. Future research on the specific causes of visual impairment may help in estimating the avoidable public health burden.

Relationship of health-related quality of life to symptom severity in diabetes mellitus: a study in Trinidad and Tobago

Our objective was to estimate the effect of greater symptom severity in diabetes mellitus on measures of health-related quality of life in a cross-sectional design in 35 government primary care health centres in Trinidad. Data were gathered on 2,117 subjects with clinical diabetes and analysed for 1,880 (89%). For each scale of the short form 36 (SF-36) questionnaire (a generic measure of health-related quality of life), scores were presented by quartile of symptom severity, measured using the Diabetes Symptom Checklist. Mean (SD) SF-36 scores were 44 (10) for the physical component score (PCS) and 45 (12) for the mental component score (MCS). Greater severity of diabetic symptoms was associated with lower scores on each of the subscales of the SF-36. Comparing lowest and highest quartiles of DSC score, the adjusted difference in PCS was -11 (95% confidence interval -12 to -9) and for MCS -16 (-18 to -14). Our results provide standardised data for health related quality of life in relation to severity of illness from diabetes, these might be used to aid the evaluation of relevant interventions.

Influence of age-related maculopathy on visual functioning and health-related quality of life

PURPOSE

To describe the influence of age-related maculopathy on visual functioning and health-related quality of life.

METHODS

A prospective, cross-sectional, observational cohort sample of 201 persons with various stages of age-related maculopathy was recruited from the Massachusetts Eye and Ear Infirmary as part of a longitudinal study of age-related macular degeneration. Persons were considered to have age-related maculopathy if one or more of the following clinical characteristics were present: drusen, retinal pigment epithelial changes, geographic atrophy, or evidence of exudative disease. Median corrected visual acuity for this sample was 20/25 in the better eye, with all subjects having 20/200 or better visual acuity in at least one eye at baseline. All participants underwent a comprehensive ophthalmologic examination with a dilated pupil. In addition to the usual clinical data collection, severity of age-related maculopathy was graded by an ophthalmologist who used standard clinical criteria and was masked to the participants' descriptions of visual functioning and health-related quality of life. All participants completed an interview that included the Activities of Daily Vision Scale, a survey designed to assess difficulties with routine daily activities that require vision, and the Short Form-36 Health Survey, a generic measure of multidimensional health-related quality of life.

RESULTS

Severity of age-related maculopathy was associated with poorer scores of the Activities of Daily Vision Scale. This association was most significant for near vision and driving activities. In this sample, the SF-36 Health Survey scales were not significantly correlated with severity of age-related maculopathy.

CONCLUSIONS

Reported visual functioning is significantly associated with the clinical severity of age-related maculopathy. However, once visual acuity is taken into consideration, clinical grading of age-related maculopathy did not explain a significant portion of the variation in visual functioning. The lack of significant correlation between severity of age-related maculopathy and the SF-36 Health Survey may have resulted from the small number of participants in our sample with severe bilateral age-related maculopathy.