+Psychometric evaluation of the MacDQoL individualised measure of the impact of macular degeneration on quality of life

2022 Glenn A. Fry Award lecture: Enhancing clinical assessment for improved ophthalmic management

ABSTRACT

Detailed clinical assessment is critical to allow sensitive evaluation of the eye and its management. As technology advances, these assessment techniques can be adapted and refined to improve the detection of pathological changes of ocular tissue and their impact on visual function. Enhancements in optical medical devices including spectacle, contact, and intraocular lenses have allowed for a better understanding of the mechanism and amelioration of presbyopia and myopia control. Advancements in imaging technology have enabled improved quantification of the tear film and ocular surface, informing diagnosis and treatment strategies. Miniaturized electronics, large processing power, and in-built sensors in smartphones and tablets capacitate more portable assessment tools for clinicians, facilitate self-monitoring and treatment compliance, and aid communication with patients. This article gives an overview of how technology has been used in many areas of eye care to improve assessments and treatment and provides a snapshot of some of my studies validating and using technology to inform better evidence-based patient management.

Validation of the Spanish version of the Low Vision Quality of Life Questionnaire

PURPOSE

To validate the Spanish Low Vision Qualify of Life (SLVQOL) questionnaire, a quality of life instrument specifically designed for patients with visual impairment, and evaluate its psychometric properties.

METHODS

The study included 170 visually impaired patients and 195 healthy subjects. Participants were administered the SLVQOL, the NEI VFQ-25, and the EQ 5D-5L questionnaires. Reliability, test-retest reproducibility, feasibility, and construct validity of the SLVQOL were assessed. The Generalized Partial Credit Model was used to fit the data and the performance of each item was characterized using category response curves and item information.

RESULTS

The reliability of the SLVQOL was 0.981 (95% CI: 0.978-0.985). Test-retest reproducibility was good (ρ=0.864, P<.001). A cut-off point of 105 or 106 was optimal to detect visual impairment, with a sensitivity of 95.4% and a specificity of 91.8%. Construct validity was shown by the corresponding convergence or divergence correlations between the score of the SLVQOL and its dimensions and the overall and partial scores of the NEI VFQ-25 and the EQ 5D-5L. Item response theory analysis showed discrimination and information parameters ranging from 0.539 to 3.063 and from -1.894 to 1.074, respectively.

CONCLUSION

The SLVQOL was able to quantitatively assess and identify differences in the quality of life among patients with visual impairment and normal subjects. The evaluated psychometric properties suggest that this tool has excellent validity, internal consistency, and reproducibility, but may benefit from a reduction of the number of items.

Identifying the content for an item bank and computerized adaptive testing system to measure the impact of age-related macular degeneration on health-related quality of life

PURPOSE

We are developing an age-related macular degeneration (AMD) health-related quality of life (HRQoL) item bank, applicable to Western and Asian populations. We report primarily on content generation and refinement, but also compare the HRQoL issues reported in our study with Western studies and current AMD-HRQoL questionnaires.

METHODS

In this cross-sectional, qualitative study of AMD patients attending the Singapore National Eye Centre (May-December 2019), items/domains were generated from: (1) AMD-specific questionnaires; (2) published articles; (3) focus groups/semi-structured interviews with AMD patients (n = 27); and (4) written feedback from retinal experts. Following thematic analysis, items were systematically refined to a minimally representative set and pre-tested using cognitive interviews with 16 AMD patients.

RESULTS

Of the 27 patients (mean ± standard deviation age 67.9 ± 7.0; 59.2% male), 18 (66.7%), two (7.4%), and seven (25.9%) had no, early-intermediate, and late/advanced AMD (better eye), respectively. Whilst some HRQoL issues, e.g. activity limitation, mobility, lighting, and concerns were similarly reported by Western patients and covered by other questionnaires, others like anxiety about intravitreal injections, work tasks, and financial dependency were novel. Overall, 462 items within seven independent HRQoL domains were identified: Activity limitation, Lighting, Mobility, Emotional, Concerns, AMD management, and Work. Following item refinement, items were reduced to 219, with 31 items undergoing amendment.

CONCLUSION

Our 7-domain, 219-item AMD-specific HRQoL instrument will undergo psychometric testing and calibration for computerized adaptive testing. The future instrument will enable users to precisely, rapidly, and comprehensively quantify the HRQoL impact of AMD and associated treatments, with item coverage relevant across several populations.

The impact of vision impairment on vision-related quality of life of patients with neovascular age-related macular degeneration

PURPOSE

To investigate the validity and reliability of the Greek Impact of Vision Impairment Questionnaire (IVI) and to explore the predictors of vision-related quality of life (VRQoL) in individuals with neovascular age-related macular degeneration (nAMD).

METHODS

About 191 patients completed the IVI and the SF-12 Health Survey, and were assessed on visual exams. A random group of 20 participants completed the IVI twice with a 2 weeks interval, to assess test-retest reliability. About 102 patients completed the IVI 1 year later in a follow-up examination. Rasch analysis was used to evaluate response category functioning, scale precision, unidimensionality, scale targeting and differential item functioning. Stepwise multiple linear regression analyses identified predictors of VRQoL.

RESULTS

Test-retest reliability of IVI items was calculated from 0.86 to 0.98. The six response categories were merged into four to figure out disordered thresholds. Rasch analysis concluded in three scales: Mobility and Independence, Reading and Accessing Information, and Emotional Wellbeing. Regarding convergent validity, the IVI scores had significant associations with SF-12 components (ρ = 0.28-0.47) and measurements of visual acuity (ρ = 0.39-0.66). Worse VRQoL at 1 year follow-up was correlated with decline in distance and near VA. Distance VA and the SF-12 components were common predictors for all three subscales. The duration of disease was a significant predictor for the emotional subscale.

CONCLUSION

The Greek IVI was found to assess AMD patients' perceptions of VRQoL in a valid, reliable and responsive to eyesight manner. VRQoL was mainly established by patients' distance VA and mental health.

Psychometric validation of three new condition-specific questionnaires to assess quality of life, symptoms and treatment satisfaction of patients with aortic aneurysm

BACKGROUND

To evaluate the psychometric properties of three new condition-specific questionnaires designed to assess outcomes amongst patients under pre-operative surveillance for a small abdominal aortic aneurysm (AAA) or who have undergone aneurysm repair. These tools are the Aneurysm-Dependent Quality of Life measure (AneurysmDQoL), the Aneurysm Symptom Rating Questionnaire (AneurysmSRQ) and the Aneurysm Treatment Satisfaction Questionnaire (AneurysmTSQ).

RESULTS

The questionnaires were sent to 297 patients with abdominal aortic aneurysm (AAA) or who had undergone AAA repair (using open or endovascular technique) sampled from five UK NHS Trusts. Exploratory Factor Analysis was used to examine factor structure together with reliability analysis. A subset of 65 patients completed the questionnaires a second time four months later. One hundred and ninety-seven patients (178 men; 18 women) provided data for analysis (69% response rate): mean age was 75 years (range 60-95). Nineteen were under pre-operative surveillance for AAA and 178 had undergone AAA repair (70 open repair; 104 endovascular repair; 4 uncertain). Exploratory Factor Analysis of the AneurysmDQoL and the AneurysmTSQ each demonstrated a one-factor structure. The AneurysmSRQ demonstrated a six-factor structure (emotional, weight loss, lower limb, cognitive, general malaise and gastrointestinal symptoms) and a one-factor composite symptom scale. All scales have clean factor structures: item loadings above 0.40, no cross-loadings, and no factors with fewer than three items. Internal consistency reliability was excellent (α = 0.869-0.959) and test-retest reliability good (Intraclass correlation coefficient = 0.70-0.88).

CONCLUSIONS

The three new questionnaires have a clear structure and strong reliability and are now ready for use in clinical trials and routine practice, which will allow evaluation of responsiveness to change.

Impacts of impaired face perception on social interactions and quality of life in age-related macular degeneration: A qualitative study and new community resources

Aims

Previous studies and community information about everyday difficulties in age-related macular degeneration (AMD) have focussed on domains such as reading and driving. Here, we provide the first in-depth examination of how impaired face perception impacts social interactions and quality of life in AMD. We also develop a Faces and Social Life in AMD brochure and information sheet, plus accompanying conversation starter, aimed at AMD patients and those who interact with them (family, friends, nursing home staff).

Method

Semi-structured face-to-face interviews were conducted with 21 AMD patients covering the full range from mild vision loss to legally blind. Thematic analysis was used to explore the range of patient experiences.

Results

Patients reported faces appeared blurred and/or distorted. They described recurrent failures to recognise others' identity, facial expressions and emotional states, plus failures of alternative non-face strategies (e.g., hairstyle, voice). They reported failures to follow social nuances (e.g., to pick up that someone was joking), and feelings of missing out ('I can't join in'). Concern about offending others (e.g., by unintentionally ignoring them) was common, as were concerns of appearing fraudulent ('Other people don't understand'). Many reported social disengagement. Many reported specifically face-perception-related reductions in social life, confidence, and quality of life. All effects were observed even with only mild vision loss. Patients endorsed the value of our Faces and Social Life in AMD Information Sheet, developed from the interview results, and supported future technological assistance (digital image enhancement).

Conclusion

Poor face perception in AMD is an important domain contributing to impaired social interactions and quality of life. This domain should be directly assessed in quantitative quality of life measures, and in resources designed to improve community understanding. The identity-related social difficulties mirror those in prosopagnosia, of cortical rather than retinal origin, implying findings may generalise to all low-vision disorders.

Domains of health-related quality of life in age-related macular degeneration: a qualitative study in the Chinese cultural context

OBJECTIVE

To explore which areas of health-related quality of life were affected in Chinese patients, and to identify whether the areas are well covered by validated questionnaires.

DESIGN

A qualitative study based on semistructured interviews was conducted. A qualitative thematic analysis following the approach of Colaizzi was used to analyse the interview data for significant statements and phrases. The themes and subthemes organised from the analysis were then compared by using the following current instruments: National Eye Institute Visual Function Questionnaire (NEI-VFQ-25), Macular Disease Quality of life Questionnaire (MacDQoL) and Low-Luminance Questionnaire (LLD).

PARTICIPANTS AND SETTING

Twenty-one patients with age-related macular degeneration were recruited from the eye clinic of Southwest Eye Hospital in Chongqing, mainland China.

RESULTS

The mean age of the participants was 69.8 years (range 57-82 years) and the duration of the disease ranged from 3 months to 6 years. The qualitative analysis revealed nine important domains including symptoms, difficulties with daily activities, depending on others, depression and uncertainty, optimism and hope, social isolation, role change, family support and financial burden. However, all the three questionnaires were insufficient to capture the full extent of quality of life issues of Chinese patients with AMD, and MacDQoL covered more domains when compared with NEI-VFQ-25 and LLD.

CONCLUSION

The domains of concepts important to people with AMD in the Chinese culture are not fully represented in the three widely used questionnaires. Nine important domains were identified for the assessment of quality of life and should be considered when assessing the impact of AMD on Chinese individuals. Further studies are needed to develop an AMD quality of life questionnaire, better tailored to the needs and culture of Chinese patients.

Treatment satisfaction of patients with neovascular age-related macular degeneration treated with anti-vascular endothelial growth factor agents

PURPOSE

To assess the psychometric properties of the Greek Macular Disease Treatment Satisfaction Questionnaire (MacTSQ) and evaluate the factors that influence treatment satisfaction of patients with neovascular age-related macular degeneration (nAMD).

METHODS

The MacTSQ was translated into Greek and administered to 176 patients. All patients completed the SF-12 Health Survey and the Macular disease Dependent Quality of Life Questionnaire (MacDQoL) and underwent vision measurements. For test-retest reliability, a subset of 19 participants completed the MacTSQ twice, two weeks apart. Stepwise multiple linear regression analyses were performed to identify predictors of treatment satisfaction. Change in MacTSQ scores over time was assessed on 83 patients who completed the MacTSQ at a follow-up visit, one year later.

RESULTS

The intraclass correlation coefficients between the first and second test-retest administration ranged from 0.88 to 0.98 for the items and total score. Internal reliability of the total score was adequate (Cronbach's a = 0.837). Principal component analysis revealed three subscales (effectiveness, information provision and convenience, impact). The MacTSQ score showed significant correlations with SF-12 summary scales and MacDQoL scores (ρ = 0.16-0.27). The most important factor that determined the satisfaction was mental health. Distance visual acuity (VA) in better eye was the best predictor of the effectiveness subscale, and the total number of injections was a negative predictor for the convenience subscale. Treatment satisfaction increased at one-year follow-up, despite the deterioration in distance VA.

CONCLUSIONS

The Greek MacTSQ is a reliable and valid instrument for assessing nAMD patients' perceptions of treatment satisfaction, especially using its three new subscales. Treatment satisfaction is multifactorial and was primarily determined by patients' mental health status.

Reliability, validity and responsiveness of the Greek MacDQoL individualized measure of the impact of macular degeneration on quality of life

PURPOSE

To assess the psychometric properties of the Greek Macular Disease-Dependent Quality of Life Questionnaire (MacDQoL).

METHODS

The MacDQoL was translated in Greek and administered to 191 patients with neovascular age-related macular degeneration (AMD). To assess validity, all patients completed the Greek SF-12 health survey and underwent vision measurements. For test-retest reliability, a subset of twenty participants completed the MacDQoL twice, 2 weeks apart. Responsiveness was assessed on 102 patients who completed the MacDQoL at a follow-up visit, 1 year later. Rasch analysis was used to assess the Greek MacDQoL's response category functioning, precision, unidimensionality, targeting and differential item functioning.

RESULTS

Internal and test-retest reliability of the average weighted impact (AWI) was 0.952 and 0.97, respectively. Test-retest reliability of MacDQoL items ranged from 0.78 to 0.99. Principal component analysis revealed three subscales (activities, embarrassment and family life), which were also confirmed by confirmatory factor analysis. Rasch analysis revealed poor functionality of response categories and that was resolved by collapsing response categories and using the impairment scores only. In terms of convergent validity, the AWI and revised MacDQoL scales showed significant correlations with SF-12 summary scales (ρ = 0.21-0.30) and vision assessments (ρ = 0.31-0.46). Poorer AMD-related QoL at 1-year follow-up was associated with deterioration in distance visual acuity and worse eye near visual acuity.

CONCLUSIONS

The Greek MacDQoL is a reliable, valid and sensitive to change in vision instrument for assessing AMD patients' perceptions of QoL. However, Rasch analysis revealed that its multiplicative rating scale is flawed. Scientific measurement was restored with a number of revisions to the questionnaire.

Distinguishing between Better and Worse Visual Acuity by Studying the Correlation with Quality of Life in Neovascular Age-Related Macular Degeneration

PURPOSE

To determine whether there is a level of visual acuity (VA) in neovascular age-related macular degeneration (nAMD) above which the correlation of VA with disease-related quality of life (QoL) is significantly greater than below this level.

DESIGN

An observational, cross-sectional study.

PARTICIPANTS

A total of 184 patients with nAMD aged at least 50 years were included in the study.

METHODS

In face-to-face interviews, we assessed QoL with the Macular Disease-Dependent Quality of Life (MacDQoL) questionnaire. We measured VA with standardized Radner reading charts. We used regression splines analysis with a single hinge point, with the MacDQoL score as the dependent variable and VA as the independent variable. The x-coordinate (VA) of the hinge point was varied and tested with each iteration. A second method of regression splines analysis was also performed, without a preset hinge point.

MAIN OUTCOME MEASURES

The primary outcome measure is the cutoff point at or below which VA is associated with significantly less change in QoL than above this cutoff. The linear coefficients below and above the cutoff are defined as change in MacDQoL score per logarithm of the minimum angle of resolution (logMAR) unit of change in VA.

RESULTS

With Snellen equivalent VA 0.05 (1.3 logMAR) or worse, the linear coefficient was 0.15. With VA better than 0.05, the linear coefficient was 2.40 (P value of the difference: 0.009).

CONCLUSIONS

When VA is above 0.05, there is a stronger and significant relation between VA and QoL. At or below this level, the relation between VA and QoL approaches zero. With better VA, a difference in VA implies a significant difference in QoL. With poorer VA, a difference in VA is unlikely to imply a difference in QoL. Therefore, in treating nAMD, the aim should be to keep Snellen VA above 0.05 to have an impact on QoL. If it is certain that the best-corrected VA below 0.05 is permanent, these findings imply there may be less, if any, benefit to continue further treatment. This is to be evaluated on a case-by-case basis.

Treatment satisfaction of patients undergoing ranibizumab therapy for neovascular age-related macular degeneration in a real-life setting

CONTEXT

Treatment satisfaction with a loading phase of monthly injections for 3 months followed by a pro-re-nata regimen of ranibizumab in neovascular age-related macular degeneration (nAMD) remains unclear.

AIMS

The aim was to evaluate the treatment satisfaction of persons with nAMD treated with ranibizumab in a real-life setting.

SETTINGS AND DESIGN

A cross-sectional study was conducted across three eye clinics within the National Health Service in the UK, where treatment is provided free at point of contact.

MATERIALS AND METHODS

A total of 250 patients were selected randomly for the study. Treatment satisfaction was assessed using the Macular Treatment Satisfaction Questionnaire. Data were collected on satisfaction of the service provided (Client Service Questionnaire-8) and the patients' demographic and quality of life and treatment history. Factors governing treatment questionnaire were determined.

RESULTS

The most important factors that determined the satisfaction were the service provided at the clinic (Client Service Questionnaire-8), health-related quality of life (EQ-5D-3L), and duration of AMD. Visual acuity changes were rated as less important than one would have expected.

CONCLUSION

The study result suggested that treatment satisfaction for nAMD was governed by the perception of being reviewed and injected regularly over a long period of time than the actual change in visual acuity from the treatment.

Generic and disease-specific estimates of quality of life in macular degeneration: mapping the MacDQoL onto the EQ-5D-3L

PURPOSE

The macular degeneration quality of life (MacDQoL) instrument is a validated condition-specific measure of quality of life in patients with macular degeneration. This paper presents the first mapping algorithm to predict EQ-5D from responses to the MacDQoL instrument.

METHODS

Responses to the MacDQoL and EQ-5D-3L instruments from 482 patients were collected from the IVAN multicentre trial of two alternative drug treatments for neovascular age-related macular degeneration. Regression specifications were estimated using OLS, censored least absolute deviation, Tobit and two-part models. Their predictive performance was assessed using mean squared error. An internal validation sample based on a random selection of 25 % of patients was used to assess the performance of the model estimated on the remaining 75 % of patients.

RESULTS

A two-part model had the best predictive performance on the full sample. The covariates of this model include responses and weighted impact scores for all 23 condition-specific domains of the MacDQoL, and responses to a general MacDQoL quality of life question. The selected models were successful at predicting means and standard deviations of target populations, but prediction is weaker at the upper and lower extremes of the EQ-5D-3L distribution.

CONCLUSION

The mapping algorithms provide a means of predicting EQ-5D-3L index scores from MacDQoL scores, and could facilitate cost-effectiveness analyses when the latter but not the former are available to researchers. Further validation of the performance of the algorithms using external data would provide a means of establishing the robustness of the algorithms.

Quality of Life with Macular Degeneration Is Not as Dark as It May Seem: Patients' Perceptions of the MacDQoL Questionnaire

To determine the perceived relevance and value of an individualized measure of the impact of macular degeneration on quality of life (QoL) for elderly people with Age-Related Macular Degeneration (AMD) in the USA, through the assessment of the suitability of the measure’s domains and by gaining a deeper insight into the impact of AMD on patients’ QoL vis-á-vis these domains, community-dwelling older adults in the metropolitan Salt Lake City, Utah area were interviewed using the macular degeneration on quality of life (MacDQoL) instrument. Participants felt that the MacDQoL was a relevant instrument for use in this US study population, though it could be improved by adding items pertaining to transportation, and independent driving, in particular, as an important QoL indicator. The emerging theme from analysis of the respondent’s commentary was that, in spite of AMD, these respondents were committed to engage in, and enjoy life. This is an important concept for clinicians and those who offer support programs to integrate into their care planning and reinforce in messaging to patients with the condition.

Enhanced text spacing improves reading performance in individuals with macular disease

The search by many investigators for a solution to the reading problems encountered by individuals with no central vision has been long and, to date, not very fruitful. Most textual manipulations, including font size, have led to only modest gains in reading speed. Previous work on spatial integrative properties of peripheral retina suggests that ‘visual crowding’ may be a major factor contributing to inefficient reading. Crowding refers to the fact that juxtaposed targets viewed eccentrically may be difficult to identify. The purpose of this study was to assess the combined effects of line spacing and word spacing on the ability of individuals with age-related macular degeneration (ARMD) to read short passages of text that were printed with either high (87.5%) or low contrast (17.5%) letters. Low contrast text was used to avoid potential ceiling effects and to mimic a possible reduction in letter contrast with light scatter from media opacities. For both low and high contrast text, the fastest reading speeds we measured were for passages of text with double line and double word spacing. In comparison with standard single spacing, double word/line spacing increased reading speed by approximately 26% with high contrast text (p < 0.001), and by 46% with low contrast text (p < 0.001). In addition, double line/word spacing more than halved the number of reading errors obtained with single spaced text. We compare our results with previous reading studies on ARMD patients, and conclude that crowding is detrimental to reading and that its effects can be reduced with enhanced text spacing. Spacing is particularly important when the contrast of the text is reduced, as may occur with intraocular light scatter or poor viewing conditions. We recommend that macular disease patients should employ double line spacing and double-character word spacing to maximize their reading efficiency.

Assessing the impact of diabetes on the quality of life of older adults living in a care home: validation of the ADDQoL Senior

AIMS

Around a quarter of UK care-home residents have diabetes. Diabetes is known to impact quality of life but existing diabetes-specific quality of life measures are unsuitable for elderly care-home residents. We aimed to develop and evaluate a new measure for use with older adults, to be particularly suitable for use with care-home residents: the Audit of Diabetes-Dependent Quality of Life (ADDQoL) Senior*.

METHODS

Content and format changes were made to the 19-domain ADDQoL, informed by related measures for people with visual impairments (12 domain-specific items were retained, four items were revised/added and three items were removed). This revision was modified further following cognitive debriefing interviews with three older adults living in a care home. Psychometric evaluation of the newly developed 17-domain ADDQoL Senior was conducted using data from 90 care-home residents with diabetes who took part in a broader intervention study.

RESULTS

The life domains most impacted by diabetes were 'independence' and 'freedom to eat as I wish'. The ADDQoL Senior demonstrated good factor structure and internal consistency (Cronbach's alpha = 0.924). Domain scores were, as expected, significantly intercorrelated.

CONCLUSIONS

The ADDQoL Senior measures the perceived impact of diabetes on quality of life in older adults, and has been found to be suitable for those living in care homes if administered by interview. The scale has demonstrated acceptability and excellent psychometric properties. It is anticipated that the number of items may be reduced in the future if our current findings can be replicated.

Assessing visual activities of daily living in the visually impaired

PURPOSE

Visual function assessment questionnaires ask people to rate the difficulty they have performing visual activities of daily living (ADLs). This study examines the relationship between self-reported difficulty and actual performance in such ADLs.

METHODS

Twenty four subjects with established bilateral visual impairment initially self-reported their difficulty with 4 ADLs (reading newsprint, reading medicine labels, identifying coins and entering a PIN). Subjects' performance in variants of these ADLs was then assessed by measuring the time taken; by an observer rating subjects' performance; and by the subject rating their perceived difficulty with each specific task. Clinical visual function parameters were also assessed.

RESULTS

Varying the assessed ADL task changed how well the task correlated with self-reported difficulty. Clinical visual function, rate of task completion and observer rating of difficulty all correlated significantly with self-reported difficulty, explaining up to 69% of the variance in self-reported difficulty. However, despite replicating the ADLs as closely as possible in the clinical environment the perceived difficulty of the clinic tasks was rated as being less than the initial self-reported difficulty of the real-world task.

CONCLUSIONS

The task variant used is important when assessing functional visual performance directly. Timed and observer-rated methods of assessment can be appropriate for assessing functional vision. In this small study, the disconnect between self-reported visual difficulty and perceived or assessed difficulty suggests that functional performance is not the only factor influencing self-report, and responses to visual function assessment questionnaires should be interpreted in this light.

Psychometric development of the individualized Retinopathy-Dependent Quality of Life Questionnaire (RetDQoL)

OBJECTIVES

Psychometric development of the Retinopathy-Dependent Quality of Life (RetDQoL) questionnaire in a cross-sectional study of 207 German patients with diabetic retinopathy. Forty patients (19%) also had clinically significant macular edema.

METHODS

Principal component analyses identified factor structure, and Cronbach's alpha assessed internal consistencies. Construct validity was examined by testing the additional impact of macular edema and expected relationships of RetDQoL scores with visual impairment, stage of diabetic retinopathy, subscales of the SF-12, and scores of the Retinopathy Treatment Satisfaction Questionnaire (RetTSQ). Analyses were conducted using the RetDQoL's AWI score (average weighted impact of diabetic retinopathy on 26 life domains) and its two overview items (present QoL in general and retinopathy-specific QoL). Content validity was investigated using an open-ended question to identify any additional items needed.

RESULTS

A forced one-factor solution of the 26 specific weighted impact ratings showed all items except working life (applicable to 27%) to load>0.55, and Cronbach's alpha was 0.96, showing very high reliability. Greater impairment, worse diabetic retinopathy, and macular edema were associated with greater negative impact on scores. AWI correlated as expected more highly with retinopathy-specific QoL (r=0.71, P<0.01) than with present QoL (r=0.28, P<0.01). RetDQoL scores correlated moderately with SF-12 subscales (r=0.22-0.51, P<0.01) and RetTSQ scores (r=0.27-0.51, P<0.01). For six domains, >60% of patients reported no impact. No additional domains were needed.

CONCLUSIONS

The RetDQoL is valid and reliable for patients with diabetic retinopathy with or without macular edema. It may be shortened if findings are confirmed cross-culturally.

The MacDQoL individualized measure of the impact of macular degeneration on quality of life: reliability and responsiveness

PURPOSE

To investigate the MacDQoL test-retest reliability and sensitivity to change in vision over a period of one year in a sample of patients with age-related macular degeneration (AMD).

DESIGN

A prospective, observational study.

METHOD

Patients with AMD from an ophthalmologist's list (n = 135) completed the MacDQoL questionnaire by telephone interview and underwent a vision assessment on two occasions, one year apart.

RESULTS

Among participants whose vision was stable over one year (n = 87), MacDQoL scores at baseline and follow-up were highly correlated (r = 0.95; P < .0001). Twelve of the 22 scale items had intraclass correlations of >.80; only two were correlated <.7. There was no difference between baseline and follow-up scores (P = .85), indicating excellent test-retest reliability. Poorer quality of life (QoL) at follow-up, measured by the MacDQoL present QoL overview item, was associated with deterioration in both the better eye and binocular distance visual acuity [VA] (r = 0.29; P = .001, r = 0.21; P = .016, respectively; n = 135). There was a positive correlation between deterioration in the MacDQoL average weighted impact score and deterioration in both binocular near VA and reading speed (r = 0.20; P = .019, r = 0.18; P = .041, respectively; n = 135).

CONCLUSION

The MacDQoL has excellent test-retest reliability. Its sensitivity to change in vision status was demonstrated in correlational analyses. The measure indicates that the negative impact of AMD on QoL increases with increasing severity of visual impairment.

Improving treatment satisfaction and other patient-reported outcomes in people with type 2 diabetes: the role of once-daily insulin glargine

Insulin therapy becomes essential for many people with type 2 diabetes. After starting insulin, people with diabetes that is poorly controlled with oral agents typically report improved well-being and treatment satisfaction. However, healthcare professionals and people with type 2 diabetes are often reluctant to begin insulin treatment, citing concerns such as time/resources needed to educate patients, increased risks of hypoglycaemia and fear of injections, which lead them to focus on intensifying conventional oral therapy. Insulin glargine, which offers people with diabetes a once-a-day injection regimen with low risk of hypoglycaemia, is more likely to overcome such initial barriers than other more complex insulin regimens. Once-daily insulin glargine, in combination with modern glucose-dependent oral agents that do not need to be chased with food to prevent hypoglycaemia, does not require the fixed mealtimes and set amounts of carbohydrates necessary with twice-daily injection mixes and older sulphonylureas. We know that it is such dietary restrictions that cause the most damage to quality of life (QoL). To avoid damaging QoL unnecessarily and to ensure optimal satisfaction with treatment, it is important to evaluate the effects of treatment on QoL, treatment satisfaction and other patient-reported outcomes (PROs) using questionnaires validated for this purpose, such as the widely used Diabetes Treatment Satisfaction Questionnaire and the Audit of Diabetes-Dependent Quality of Life measure. A systematic electronic literature search identified reports of studies evaluating PROs associated with insulin glargine in comparison with other treatments. The studies show that insulin glargine is usually associated with greater improvements in treatment satisfaction and other PROs compared with intensifying oral therapy or alternative insulin regimens.

Living with Fear: The Lived Experience of Community Mobility among Older Adults with Low Vision

This secondary analysis of data drawn from a descriptive phenomenological study explored how older adults with low vision experience and manage community mobility. Participants included 34 urban and rural older adults, age 70 years and older, who were not using low-vision-rehabilitation services. The findings convey a core element of the experience of community mobility for participants: living with a pervasive sense of fear regarding one’s body and way of being. Participants continually gauged risks associated with mobility and engaged in risk avoidance and management strategies. Community mobility was often restricted by participants because of perceived risks, leading to reduced participation in a range of physical, social, and other types of activities. Further research on environmental factors mediating community mobility and on strategies effective in maintaining mobility among seniors with low vision is essential to optimize participation, health, and service delivery.

Quality of life and health economic assessments of age-related macular degeneration

In this article, we review measures of patient-reported outcomes that can show whether a treatment for age-related macular degeneration also provides patient-perceived benefits. In addition, we look at health economic measurements currently being used to develop cost-effectiveness models for age-related macular degeneration.

Quality of life in age-related macular degeneration: a review of the literature

BACKGROUND

The Age-related Macular Degeneration Alliance International commissioned a review of the literature on quality of life (QoL) in macular degeneration (MD) with a view to increasing awareness of MD, reducing its impact and improving services for people with MD worldwide.

METHOD

A systematic review was conducted using electronic databases, conference proceedings and key journal hand search checks. The resulting 'White Paper' was posted on the AMD Alliance website and is reproduced here.

REVIEW

MD is a chronic, largely untreatable eye condition which leads to loss of central vision needed for tasks such as reading, watching TV, driving, recognising faces. It is the most common cause of blindness in the Western world. Shock of diagnosis, coupled with lack of information and support are a common experience. Incidence of depression is twice that found in the community-dwelling elderly, fuelled by functional decline and loss of leisure activities. Some people feel suicidal. MD threatens independence, especially when comorbidity exacerbates functional limitations. Rehabilitation, including low vision aid (LVA) provision and training, peer support and education, can improve functional and psychological outcomes but many people do not receive services likely to benefit them. Medical treatments, suitable for only a small minority of people with MD, can improve vision but most limit progress of MD, at least for a time, rather than cure. The White Paper considers difficulties associated with inappropriate use of health status measures and misinterpretation of utility values as QoL measures: evidence suggests they have poor validity in MD.

CONCLUSION

There is considerable evidence for the major damage done to QoL by MD which is underestimated by health status and utility measures. Medical treatments are limited to a small proportion of people. However, much can be done to improve QoL by early diagnosis of MD with good communication of prognosis and continuing support. Support could include provision of LVAs, peer support, education and effective help in adjusting to MD. It is vital that appropriate measures of visual function and QoL be used in building a sound evidence base for the effectiveness of rehabilitation and treatment.

Feedback on the FDA's February 2006 draft guidance on Patient Reported Outcome (PRO) measures from a developer of PRO measures

I believe that the FDA guidelines have already had an impact in encouraging good practice in the use of PROs. There are, however, important improvements that need to be made to the guidelines, particularly in the use of health status and quality of life terminology. It is essential to distinguish between health status and quality of life and to use both terms. Nothing is to be gained and a great deal will be lost if the term quality of life (which has been misused as an umbrella term in the past) is abandoned and replaced with the term health status. Patients want us to consider their quality of life as well as their health. To abandon the term would be to forget about their quality of life and focus only on their health. Patients are well able to tell us what quality of life means to them and to rate the impact of a condition on their quality of life if we use individualised quality of life measures and individualised condition-specific quality of life measures to allow them to do so. Although my experience with PRO measures would support many of the recommendations in the guidelines there are others that I would not fully agree with or would contradict on the basis of my own research evidence. I have provided references to that research and hope that the FDA will feel able to do the same when they finalize their guidelines.

Binocular function in patients with age-related macular degeneration: a review

Normally sighted observers typically benefit from binocular viewing when monocular sensitivities are equivalent. Age-related macular degeneration (AMD) not only destroys the foveal vision, however, but it also affects the 2 eyes unequally, providing grounds for impairment of binocular function. The aim of the present article is to provide a review of the current research on the effect of AMD on binocular vision. The main findings to date reveal that a high proportion of patients show characteristics of binocular contrast inhibition at low and medium spatial frequencies. Yet binocular acuity gain is not different from that of age-matched control participants without AMD. Additional findings show that rivalry processes are severely disrupted in patients with AMD. The effects of the disease on other binocular functions have yet to be explored. Knowledge of binocular function in AMD may one day help clinicians decide on the most appropriate management and rehabilitation techniques.

Preliminary development of a new individualised questionnaire measuring quality of life in older men with age-related hormonal decline: the A-RHDQoL

BACKGROUND

There is increasing interest in hormone replacement therapy to improve health and quality of life (QoL) of older men with age-related decline in hormone levels. This paper reports the preliminary development and evaluation of the psychometric properties of a new individualised questionnaire, the A-RHDQoL, measuring perceived impact of age-related hormonal decline on QoL of older men. A-RHDQoL design was based on the HDQoL for people with growth hormone (GH) deficiency and the ADDQoL (for diabetes).

METHODS

Internal consistency reliability and some aspects of validity of the A-RHDQoL were investigated in a cross-sectional survey of 128 older men (age range: 64 - 80 yrs), being screened for inclusion in a trial of GH and testosterone (T) replacement, and who completed the A-RHDQoL once. Respondents rated personally applicable life domains for importance and impact of their hormonal decline. A single overview item measured present QoL. Serum levels of Insulin-like Growth Factor-I and total T were measured.

RESULTS

Of the 24 A-RHDQoL domains, 21 were rated as relevant and important for older men. All domains were perceived as negatively impacted by hormonal decline. The most negatively impacted domains were: memory (-4.54 +/- 3.02), energy (-4.44 +/- 2.49), sex life (-4.34 +/- 3.08) and physical stamina (-4.29 +/- 2.41), (maximum range -9 to +9). The shorter 21-domain A-RHDQoL had high internal consistency reliability (Cronbach's alpha coefficient = 0.935, N = 103) and applicable domains could be weighted and summed into an overall Average Weighted Impact score. The questionnaire was acceptable to the majority of respondents and content validity was good. The single overview item measuring present QoL correlated significantly with total T levels [r = 0.26, p <0.01, N = 114].

CONCLUSION

The new 21-item A-RHDQoL is an individualised questionnaire measuring perceived impact of age-related hormonal decline on the QoL of older men. The internal consistency reliability and content validity of the A-RHDQoL are established, but the measure is at an early stage of its development and its sensitivity to change and other psychometric properties need now to be evaluated in clinical trials of hormone replacement in older men.