Measuring handicap: motives, methods, and a model

Handicap as a Measure of Perceived-Health Status in Parkinson's Disease

Background

Handicap is a patient-centered measure of health status that encompasses the impact of social and physical environment on daily living, having been assessed in advanced and late-stage Parkinson's Disease (PD).

Objective

To characterize the handicap of a broader sample of patients.

Methods

A cross-sectional study of 405 PD patients during the MDS-UPDRS Portuguese validation study, using the MDS-UPDRS, Unified Dyskinesias Rating Scale, Nonmotor symptoms questionnaire, PDQ-8 and EQ-5D-3L. Handicap was measured using the London Handicap Scale (LHS).

Results

Mean age was 64.42 (±10.3) years, mean disease duration 11.30 (±6.5) years and median HY 2 (IQR, 2-3). Mean LHS was 0.652 (±0.204); "Mobility," "Occupation" and "Physical Independence" were the most affected domains. LHS was significantly worse in patients with longer disease duration, older age and increased disability. In contrast, PDQ-8 did not differentiate age groups. Handicap was significantly correlated with disease duration (r = -0.35), nonmotor experiences of daily living (EDL) (MDS-UPDRS-I) (r = -0.51), motor EDL (MDS-UPDRS-II) (r = -0.69), motor disability (MDS-UPDRS-III) (r = -0.49), axial signs of MDS-UPDRS-III (r = -0.55), HY (r = -0.44), presence of nonmotor symptoms (r = -0.51) and PDQ-8 index (r = -0.64) (all P < 0.05). Motor EDL, MDS-UPDRS-III and PDQ-8 independently predicted Handicap (adjusted R 2 = 0.582; P = 0.007).

Conclusions

The LHS was easily completed by patients and caregivers. Patients were mild-moderately handicapped, which was strongly determined by motor disability and its impact on EDL, and poor QoL. Despite correlated, handicap and QoL seem to differ in what they measure, and handicap may have an added value to QoL. Handicap seems to be a good measure of perceived-health status in a broad sample of PD.

A content analysis of peripheral arterial disease patient-reported outcome measures using the International Classification of Functioning, Disability and Health

BACKGROUND

The purpose of this study was to link, classify and describe the content of peripheral arterial disease (PAD)-specific patient-reported outcome measures using the International Classification of Functioning. The results were then analyzed to determine if these assessments provide clinicians and researchers with a comprehensive understanding of the lived experience of patients with PAD.

METHODS

Each meaningful concept in identified PAD assessments was linked to the International Classification of Functioning, Disability and Health to determine included and excluded content areas. An overall perspective was assigned to each assessment item. Inter-rater reliability was established using a kappa statistic.

RESULTS

The body functions component is most frequently addressed overall followed by the activities and participation component. International Classification of Functioning chapter and category distribution vary greatly between assessments and no assessment comprehensively examines community participation and relationships. The majority of the assessment items are of the health status-disability and quality of life perspectives.

CONCLUSIONS

The results of this study suggest the need for the development of a comprehensive PAD assessment that includes a more even distribution of International Classification of Functioning topics and subtopics. A more comprehensive assessment would better capture the lived experience of this patient population. Implications for Rehabilitation A better understanding of the data collected using the current peripheral arterial disease-specific patient-reported outcome measures may contribute to the development of more comprehensive assessment tools that will ultimately lead to improved patient care. This study contributes to the preliminary foundation for the development of a peripheral arterial disease International Classification of Functioning, Disability and Health Core Set. Clinicians and researchers interested in using peripheral arterial disease-specific patient-reported outcome measures for clinical and research purposes can better understand what topics are included and excluded in the collection and what perspectives are addressed.

Disability in Activities of Daily Living and Severity of Dyskinesias Determine the Handicap of Parkinson's Disease Patients in Advanced Stage Selected to DBS

BACKGROUND

There is scarce data on the level of handicap in Parkinson's disease (PD) and none in advanced stage PD.

OBJECTIVE

To assess the handicap in advanced stage PD patients with disabling levodopa-induced motor complications selected to deep brain stimulation (DBS).

METHODS

Data was prospectively recorded during routine evaluation for DBS. Handicap was measured using London Handicap Scale (LHS) (0 = maximal handicap; 1 = no handicap). Disease severity was evaluated using the Hoehn & Yahr scale and the UPDRS/MDS-UPDRS, during off and on after a supra-maximal dose of levodopa. Schwab and England Scale (S&E) was scored in off and on. Dyskinesias were scored using the modified Abnormal Involuntary Movement Scale (mAIMS). Results concern cross-sectional assessment before DBS.

RESULTS

100 PD patients (mean age 61 (±7.6); mean disease duration 12.20 (±4.6) years) were included. Median score of motor MDS-UPDRS was 54 in off and 25 in on. Mean total LHS score was 0.56 (±0.14). Patients were handicapped in several domains with a wide range of severity. Physical Independence and Social Integration were the most affected domains. Determinants of total LHS score were MDS-UPDRS part II off (β= -0.271; p = 0.020), S&E on (β= 0.264; p = 0.005) and off (β= 0.226; p = 0.020), and mAIMS on (β= -0.183; p = 0.042) scores (R2  = 29.6%).

CONCLUSIONS

We were able to use handicap to measure overall health condition in advanced stage PD. Patients were moderately to highly handicapped and this was strongly determined by disability in ADL and dyskinesias. Change in handicap may be a good patient-centred outcome to assess efficiency of DBS.

Changing everyday activities of couples in late life: converging and keeping up

The influence of mutual spousal interrelations in domains such as health and wellbeing has been demonstrated, but little is known about the domain of everyday activities of couples in late life. In the present explorative study, we considered all of the activities participating couples talked about to be their everyday activities. Its aim was to understand, over time, changes in everyday activities as experienced by late-life community-dwelling couples. In a two-year period, 41 individual and joint interviews were conducted with 8 couples, who were purposefully selected from the Longitudinal Aging Study Amsterdam. Analyses involved the construction of couple narratives and constant comparisons within and across couples. Changing everyday activities in late-life couples was interpreted to be a two-way process of (1) converging, and (2) keeping up, which occurred in three fluid phases. Converging was a slow inward movement with a shift towards diminished everyday activities performed in a smaller world. Keeping up was an outward movement in order to resist the converging process by using everyday activities as a means to keep fit, physically and mentally, and to connect with the wider social world. In the first phase, couples maintained their unique linked activity pattern. In the second phase, spouses resisted converging by keeping up. In the third phase, spouses co-performed everyday activities closely together. The findings support the need to develop couple-oriented interventions that aim to enhance the couples' functioning in the domain of everyday activities.

Measuring participation after stroke: a review of frequently used tools

OBJECTIVE

To identify and critique the measures currently used to assess participation in clinical stroke studies.

DATA SOURCES

Relevant articles published between January 2001 and April 2012 identified through Medline, CINAHL, and ProQuest Central databases.

STUDY SELECTION

Published articles involving poststroke assessment of participation. Case studies, cohort studies, and randomized controlled trials were included.

DATA EXTRACTION

The most frequently used measures were identified and the psychometric properties evaluated. Three raters independently evaluated each measure relative to the first and second coding levels of the International Classification of Functioning, Disability and Health (ICF) Activities and Participation domain categories.

DATA SYNTHESIS

Thirty-six measures were identified. The Stroke Impact Scale (SIS), London Handicap Scale, Assessment of Life Habits (LIFE-H), Frenchay Activities Index, and Activity Card Sort (ACS) were used most frequently. No single measure met criteria across all psychometric indices, and not one covered all 9 of the ICF Activities and Participation domains. The SIS, LIFE-H, and ACS covered the widest range. The domains covered most frequently were Community, Social and Civic Life, Domestic Life, and Mobility. Learning and Applying Knowledge, General Tasks and Demands, and Communication were the domains less frequently covered.

CONCLUSIONS

This review identified and evaluated the most frequently used participation measures in clinical stroke studies. The SIS, LIFE-H, and ACS covered the ICF Activities and Participation domain categories most comprehensively. However, none of the measures covered all the ICF Activities and Participation domain categories. The information provided in this systematic review can be used to guide the selection of participation measures to meet specific clinical and research purposes.

Onset and persistence of person-perceived participation restriction in older adults: a 3-year follow-up study in the general population

Background

Participation restriction is defined as "problems an individual may experience in involvement in life situations" and refers to the personal and societal consequences of health conditions. There is a growing interest in participation restriction because (i) problems with work or looking after others may be more concerning to individuals than the signs and symptoms of health conditions and (ii) even when poor health persists, participation may still be maintained. The natural history of participation restriction in the general population is unknown and the aim of this report is to describe change in status of person-perceived participation restriction over three years in community-dwelling adults aged 50 years and over.

Method

Prospective cohort study (baseline and 3-year follow-up) using postal questionnaires mailed to a population-based sample of older adults. Responders were included in this study if they completed all items of the Keele Assessment of Participation at baseline (n = 6965). Estimates of onset and persistence of person-perceived participation restriction at 3-year follow-up were calculated for any and for each aspect of life in the sample as a whole, and then by age and gender using attrition re-weighted logistic regression to take account of sample attrition.

Results

In the whole sample of 6965 persons, overall participation status at three years was unchanged in 69%, and changed in 31%. Of 3431 persons with no restriction at baseline, it is estimated that 29.8% (95% confidence interval: 27.6%, 32.0%) would report restriction in at least one aspect of life at 3-year follow-up. Of 3534 persons who had baseline restriction, it is estimated that 68.8% (66.2%, 71.3%) would report continuing restriction in at least one aspect of life after 3 years. Onset and persistence both increased with age, and were most frequently recorded for restricted mobility outside the home.

Conclusion

Although most older persons do not change their overall participation status during a three-year period, change does occur which implies that population approaches to improving participation can be sought. Both onset and persistence of person-perceived participation restriction are more common the older the age-group.

Factors associated with restricted mobility outside the home in community-dwelling adults ages fifty years and older with knee pain: an example of use of the International Classification of Functioning to investigate participation restriction

OBJECTIVE

To investigate the links between knee pain characteristics and restricted mobility outside the home, and how these are influenced by mobility-specific activity limitation, age, sex, socioeconomic status, environmental factors, and comorbidity.

METHODS

We conducted a cross-sectional survey of community-dwelling adults age > or = 50 years. A total of 2,252 responders reporting pain in and around the knee in the last year were eligible. The primary outcome was self-reported restricted mobility outside the home in the previous 4 weeks (dichotomized as present or absent).

RESULTS

Knee pain severity was strongly associated with restricted mobility outside the home, an association largely mediated by perceived limitation in walking. After adjusting for demographic and socioeconomic characteristics, individual contributions from selected comorbidities, knee pain severity, limitation in walking, and specific environmental factors remained. These environmental factors included perceived need of aids and assistance (adjusted odds ratio [OR] 3.1, 95% confidence interval [95% CI] 2.2-4.4), poor access to public transportation (adjusted OR 2.3, 95% CI 1.4-3.9), and having no access to a car (adjusted OR 1.6, 95% CI 1.1-2.4).

CONCLUSION

There are a range of potential health and social targets that, if addressed, might reduce restricted mobility outside the home in middle-aged and older individuals with knee pain. Our results suggest that, in addition to treating the knee symptoms, such targets might include comorbidity, walking ability, and environmental barriers such as poor access to public transportation. Moreover, removing environmental barriers may reduce immobility outside the home even in the continued presence of osteoarthritis symptoms and specific activity limitations.

Factors associated with participation restriction in community-dwelling adults aged 50 years and over

In the World Health Organization's International Classification of Functioning, Disability and Health, participation restriction--the social and personal consequences of health conditions and their environment--is an important component of the concept of disability. The cross-sectional associations between perceived participation restriction and health, demographic and socio-economic factors were examined in 7,878 community-dwelling adults aged 50 years and over in North Staffordshire, UK who responded to a postal survey. All health conditions, impairments, activity limitations, demographic and socio-economic factors were associated with participation restriction, after adjusting for age and gender in a logistic regression analysis. Health and disability factors most strongly and independently associated with participation restriction in a multivariate analysis were the number of peripheral joint pains, the number of health conditions, cognitive impairment, anxiety, depression, and activity limitation. Perceived adequacy of income, employment status and occupational class were also significantly associated with participation restriction after adjusting for health and disability factors. In conclusion, perceived participation restriction is associated with a range of health and socio-economic factors. Although further prospective research is needed to identify the direction of causal association, these factors represent potential targets for intervention to prevent or reduce participation restriction in older adults in the community.

The prevalence of person-perceived participation restriction in community-dwelling older adults

OBJECTIVE

To estimate the prevalence, nature and distribution of person-perceived participation restriction, in community-dwelling older adults.

METHOD

Population based cross-sectional postal survey of 11,055 adults aged 50 years and over in North Staffordshire, United Kingdom. Person-perceived participation restriction was measured using the Keele Assessment of Participation which covers 11 different aspects of life mapped to the World Health Organization's International Classification of Functioning. Four-week period prevalence was calculated for restriction in any, multiple and for each aspect separately. Prevalence estimates were calculated for the total sample, and for each age and gender stratum.

RESULTS

A total of 7,878 subjects responded (adjusted response--71.3%). The 4-week period prevalence of any participation restriction was 51.8%; 3.3% had substantial restriction. Participation restriction increased with age (p<0.001) and, for moderate and substantial restriction, was more frequent in women. The prevalence of restricted participation in individual aspects of life ranged from 3.8% (work) to 25.9% (mobility outside the home).

CONCLUSION

Some restriction of participation 'as and when we want it' is common in the general population and increases with age, although severe restriction only affects a minority. The distribution of person-perceived participation restriction is similar to that of impairments and activity limitation in community-dwelling older adults.

Initial validation of the Swedish version of the London Handicap Scale

OBJECTIVE

To adapt and evaluate the unweighted version of the London Handicap Scale (LHS) for use in Sweden.

MATERIALS & METHODS

Respondent burden, linguistic validity and patient perceived relevance was assessed in 16 neurologically ill patients. Internal consistency reliability and construct validity were evaluated among 89 stroke survivors six months after discharge.

RESULTS

Patients perceived the LHS as relevant and easy to understand and complete. Mean time to complete the questionnaire was 10 min. Cronbach's alpha reliability was 0.85. The LHS differentiated between patients living at home and in special accommodations. As expected, scores correlated strongly and weakly with indices of related and more remote constructs, respectively. There were no floor-, but large ceiling effects.

CONCLUSIONS

The observations reported here are in accordance with previous studies using the original British LHS and provide initial support for the reliability and validity of the instrument for use in Sweden. However, ceiling effects may limit its usefulness as an outcome measure.

The Keele Assessment of Participation: a new instrument to measure participation restriction in population studies. Combined qualitative and quantitative examination of its psychometric properties

The World Health Organization has proposed participation restriction to reflect the societal consequences of health conditions. Despite its importance, participation restriction appears to be inconsistently represented or absent from the content of many health status instruments. This paper describes the development and testing of a new self-complete measure of participation restriction from the conceptual basis of participation as an individual's perception of their actual involvement in life situations. The psychometric properties (face, content and construct validity, responder burden, performance and repeatability) of the instrument were examined using qualitative and quantitative methods. Person-perceived participation restriction did not reflect the frequency of participation but was associated with participants' expectations, aspirations, and needs, as well as contextual factors. We conclude that the instrument can provide estimates of person-perceived participation restriction in population surveys.

Measuring the consequences of osteoarthritis and joint pain in population-based studies: can existing health measurement instruments capture levels of participation?

OBJECTIVE

To identify health measurement instruments to investigate levels of participation associated with joint pain in a population survey questionnaire.

METHOD

A comprehensive electronic search of the published literature was performed to identify potential instruments that could measure participation. All items from identified instruments were assessed for the ability to measure participation by 2 experienced and 2 inexperienced assessors. Agreement was determined in terms of actual agreement (%) and agreement beyond chance (kappa).

RESULTS

Twenty-seven instruments (912 items) were identified. Agreement between the experienced assessors occurred in 86% of items (kappa = 0.70, 95% confidence interval [95% CI] 0.65-0.75) and between the inexperienced assessors in 72% (kappa = 0.40, 95% CI 0.34-0.46). The greatest proportion of participation items in one instrument was 82%.

CONCLUSION

None of the identified instruments consisted entirely of participation items. The concept of participation and its translation into measurement for use in the general population is likely to need further development.

Predictors of response to treatment for chronic fatigue syndrome

BACKGROUND

Controlled trials have shown that psychological interventions designed to encourage graded exercise can facilitate recovery from chronic fatigue syndrome.

AIMS

To identify predictors of response to psychological treatment for chronic fatigue syndrome.

METHOD

Of 114 patients assigned to equally effective treatment conditions in a randomised, controlled trial, 95 completed follow-up assessments. Relationships between variables measured prior to randomisation and changes in physical functioning and subjective handicap at 1 year were evaluated by multiple regression.

RESULTS

Poor outcome was predicted by membership of a self-help group, being in receipt of sickness benefit at the start of treatment, and dysphoria as measured by the Hospital Anxiety and Depression scale. Severity of symptoms and duration of illness were not predictors of response.

CONCLUSIONS

Poor outcome in the psychological treatment of chronic fatigue syndrome is predicted by variables that indicate resistance to accepting the therapeutic rationale, poor motivation to treatment adherence or secondary gains from illness.

Systematic review of randomized controlled trials of nonpharmacological interventions for fibromyalgia

OBJECTIVE

Little is known of the effectiveness of nonpharmacological interventions for fibromyalgia syndrome (FMS). The authors therefore carried out a systematic review from 1980 to May 2000 of randomized controlled trials (RCTs) of nonpharmacological interventions for FMS.

METHOD

A search of computerized databases was supplemented by hand searching of bibliographies of key publications. The methodological quality of studies included in the review was evaluated independently by two researchers according to a set of formal criteria. Discrepancies in scoring were resolved through discussion.

RESULTS

The review yielded 25 RCTs, and the main categories of interventions tested in the studies were exercise therapy, educational intervention, relaxation therapy, cognitive-behavioral therapy, acupuncture, and forms of hydrotherapy. Methodological quality of studies was fairly low (mean score = 49.5/100). Most studies had small samples (median for individual treatment groups after randomization = 20), and the mean power of the studies to detect a medium effect ( > or = 0.5) was 0.36. Sixteen studies had blinded outcome assessment, but patients were blinded in only 6 studies. The median longest follow-up was 16 weeks. Statistically significant between-group differences on at least one outcome variable were reported in 17 of the 24 studies.

CONCLUSIONS

The varying combinations of interventions studied in the RCTs and the wide range of outcome measures used make it hard to form conclusions across studies. Strong evidence did not emerge in respect to any single intervention, though preliminary support of moderate strength existed for aerobic exercise. There is a need for larger, more methodologically rigorous RCTs in this area.

Psychometric evaluation of a new handicap scale in immune-mediated polyneuropathies

A new handicap measure, the Rotterdam nine-item handicap scale, was developed and its validity, reliability, and responsiveness evaluated in patients with immune-mediated polyneuropathies. We evaluated 113 stable patients, of whom 83 had Guillain--Barré syndrome (GBS), 22 had chronic inflammatory demyelinating polyneuropathy (CIDP), and 8 had a gammopathy-related polyneuropathy. We also studied 20 patients with recently diagnosed GBS (n = 7) or CIDP (n = 13) and changing clinical conditions (longitudinal group). Significant discriminatory validity and correlation with the Rankin scale were demonstrated for the Rotterdam nine-item handicap scale (stable group: Spearman's test, r = minus sign.76 to minus sign.78; longitudinal group: intraclass correlation coefficient, r =.83; P <.0001). Also, good reliability (r =.89--.98; P <.0001) and high responsiveness values (standardized response mean values >.8) were obtained for the Rotterdam nine-item handicap scale. In contrast to the Rankin scale, the Rotterdam scale not only provided information regarding mobility but also highlighted physical independence, occupation, and social integration. These results illustrate the clinical usefulness of the Rotterdam nine-item handicap scale under these conditions.

Development of subscales from the symptoms/problems and effects of kidney disease scales of the kidney disease quality of life instrument

BACKGROUND

The Kidney Disease Quality of Life Instrument (KDQOL) was developed to provide clinicians with a comprehensive assessment of the important domains of health-related quality of life (HRQOL) for patients with end-stage renal disease who are undergoing hemodialysis.

OBJECTIVE

The purpose of this study was to develop subscales from the 55 items comprising the Symptoms/Problems and Effects of Kidney Disease scales of the KDQOL and to measure the internal consistency reliability of these subscales.

METHODS

The 55 items from the Symptoms/Problems and Effects of Kidney Disease scales were arranged into substantively meaningful clusters using an affinity mapping procedure. The resulting subscales were assessed for internal consistency reliability using data from a sample of 165 individuals with kidney disease who had completed the KDQOL.

RESULTS

Eleven multi-item subscales were identified: pain, psychological dependency, cognitive functioning, social functioning, dialysis-related symptoms, cardiopulmonary symptoms, sleep, energy, cramps, diet, and appetite. Four items (clotting or other problems with access site, high blood pressure, numbness in hands or feet, and blurred vision) were not included in any of these subscales. Internal consistency reliability estimates for the 11 subscales ranged from 0.66 to 0.92. These subscales correlated with the scales from the 36-Item Short-Form Health Survey as hypothesized (ie, corresponding pain, energy, and social functioning scales had the highest correlations). In addition, several subscales were significantly associated, as hypothesized, with other variables such as the number of disability days.

CONCLUSIONS

The results of this study further support the reliability and validity of the KDQOL. The 11 subscales identified yield more detailed information on the HRQOL of patients with kidney disease and provide a basis for specific improvements in the quality of care delivered to these patients.

The development of a handicap assessment questionnaire: the Impact on Participation and Autonomy (IPA)

OBJECTIVE

To report on the feasibility and psychometric properties in terms of homogeneity and construct validity of a newly developed handicap questionnaire focusing on person-perceived handicaps: the Impact on Participation and Autonomy (IPA).

DESIGN

Cross-sectional. SETTING, subjects and outcome measure: One hundred consecutive individuals from the outpatient clinic of the department of rehabilitation of an academic hospital administered the new questionnaire IPA.

RESULTS

The results show good homogeneity and construct validity of the IPA. Factor analysis showed that the scale consists of four factors, explaining 68% of the total variance: social relationships, autonomy in self-care, mobility and leisure, and family role. Homogeneity of the four subscales was considered good, Cronbach's alpha ranged from 0.84 (family role) to 0.87 (social relationships). Feasibility in terms of the number of missing values and administration time needed was satisfactory.

CONCLUSION

The first results suggest that the IPA promises to be a useful handicap questionnaire. Further research is needed to establish test-retest reliability, convergent validity and responsiveness to change.

Measuring handicap in multiple sclerosis

Handicap, shortly to be renamed participation, is a well defined though somewhat neglected entity which addresses an important aspect of the impact disease has on the individual. It is particularly relevant in Multiple Sclerosis (MS) which has such a major impact on issues such as employment, relationships, transport and social integration. Few validated measuring tools exist, and the generic London Handicap Scale is probably the best currently available but is only appropriate for group comparison. Handicap should be monitored in MS and is particularly appropriate in the evaluation of rehabilitation strategies.

New handicap scale for elderly in hospital

The new handicap scale, consisting of 12 questions based on ICD classification of handicap, was developed as an outcome measure and assessed in 29 in-patients and 27 day hospital attenders. Results show that the handicap score obtained using this new instrument correlates significantly with the score obtained using the London handicap scale. In addition the score correlated with the Nottingham extended activities of daily living, the functional autonomy measurement system, two of the commonly used measures of outcome, and some of the parameters of SF-36. In the 29 inpatients the results show improvement in handicap with treatment including rehabilitation. For assessment of reproducibility and stability over time the handicap scale was administered twice to 10-day-hospital attenders over a three days period end the results revealed a high coefficient (0.98) and kappa (0.92) values. Thus the results obtained from this small study suggest that the questionnaire is a useful tool for assessment of handicap in elderly patients receiving treatment in hospital.

A pragmatic defence of health status measures

A family of instruments has been developed over the last twenty five years in order to measure the individual's subjective view of his health. The instruments vary in how broadly they define health. A wide range of critiques have challenged both the validity of these measures and their uses. This paper argues that disproportionate attention has been given to one form of health status measure--the so-called utility-based measures. The ensuing controversies have distracted from the substantial progress achieved in the application of health status measures. This paper identifies the major areas of progress and argues that any serious critique needs to engage with this now sizeable body of applied knowledge.

Clinical and public health perspectives and applications of health-related quality of life measurement

Health-related quality of life (HRQL) measures have been developed from the utilitarian ethical perspective of public health medicine which may be contrasted with individual-centered indicators; these emphasise the unique experience of a patient. The impairment-disability-handicap framework provides a more complete description of disease consequences and health outcomes than a generic HRQL indicator. The assessment of reliability and validity of HRQL indicators is often carried out inappropriately: population repeatability is measured when an indicator will be used to examine changes in individuals; between observer variation may be large compared with variation between populations. Content and construct validity are usually measured but the more important predictive validity is neglected. Effect sizes of HRQL indicators are likely to be inflated by use of between subject estimates of variance but the more appropriate within subject variance is seldom reported. HRQL indicators are of very limited value for many clinical and public health tasks: monitoring health of individuals and populations; evaluating the effects of health and social policy; allocating resources; evaluating the effects of treatment. Alternative methods of assessment derived from the impairment-disability-handicap conceptual framework are preferable.

Measuring handicap: the London Handicap Scale, a new outcome measure for chronic disease

OBJECTIVE

To develop a handicap measurement scale in a self completion questionnaire format, with scale weights allowing quantification of handicap at an interval level of measurement.

DESIGN

Adaptation of the International Classification of Impairments, Disabilities and handicaps into a practical questionnaire incorporating the dimensions of handicap mobility, occupation, physical independence, social integration, orientation, and economic self sufficiency and scale weights derived from interviews with a general population sample, with the technique of conjoint analysis.

SETTING

Two general practices in different areas of London.

SUBJECTS

240 adults aged 55-74 years randomly selected from the practices, 101 (42%) of whom agreed to be interviewed, and 79 (78%) of whom completed the exercise.

MAIN MEASURES

Rating of severity of handicap associated with 30 hypothetical health scenarios on a visual analogue scale, from which was derived a matrix of scale weights ("part utilities") relating to different levels of disadvantage on each dimension, with a formula for combining them into an overall handicap score. Severity scores measured directly for five scenarios not used to derive the scale weights were compared with those calculated from the formula to validate the model.

RESULTS

The part utilities obtained conformed with the expected hierarchy for each dimension, confirming the validity of the method. The measured severities and those calculated from the formula for the five scenarios used to validate the model agreed closely (Pearson's r = 0.98, p = 0.0009; Kendall's tau = 1.00, p = 0.007).

CONCLUSIONS

This interval level handicap measurement scale will be useful in assessing both specific therapies and health services, in clinical trials, in analyses of cost effectiveness, and in assessments of quality assurance.