Measuring autonomy in disabled people: validation of a new scale in a UK population

Objective: To evaluate the validity and reliability of an English version of the Impact on Participation and Autonomy Questionnaire (IPA). The original Dutch IPA has been shown to load onto five factors. Design: A validation study. Setting: Outpatients clinics and people’s homes. Subjects: Two hundred and thirteen people with multiple sclerosis, rheumatoid arthritis, spinal cord injury, and general practice attendees, stratified by level of disability (median age 54, 42% male, 58% female). Inclusion criteria: English as first language, aged 18-75, Mental Status Questionnaire score >6. Interventions: Self- and interviewer-administered outcome measures. Main measures: IPA, including one new item (66 participants completed the IPA on a second occasion). Other measures: Short Form-36 Health Survey (SF-36), London Handicap Scale, three domains of the Functional Limitations Profile (FLP): household management, social integration, emotion. Results: Confirmatory factor analysis confirmed the construct validity of the IPA (Normal Fit Index=0.98, Comparative Fit Index=0.99), indicating a good fit to the model. Convergent and discriminant validity were confirmed by the predicted associations, or lack of, with the exception of a poor association between the ‘social life/relationships’ IPA subscale and FLP-emotion. Internal reliability of the IPA was confirmed (Cronbach alphas >0.8; item-total correlations for all subscales >0.5). Test-retest reliability was confirmed for all items (weighted kappas >0.6) and subscales (intraclass correlation coefficients >0.90). Conclusions: The English IPA is a valid, reliable and acceptable measure of participation and autonomy in people with a range of conditions and can make a unique and fundamental contribution to outcome assessment. Further research is required to examine the responsiveness of the IPA to change over time, its clinical utility and suitability for use with people from ethnic minorities and with older people.

[1]  M. Bergner,et al.  A cross-cultural comparison of health status values. , 1985, American journal of public health.

[2]  G. Cumming,et al.  A Primer on the Understanding, Use, and Calculation of Confidence Intervals that are Based on Central and Noncentral Distributions , 2001 .

[3]  R. Kahn,et al.  Brief objective measures for the determination of mental status in the aged. , 1960, The American journal of psychiatry.

[4]  W. Levack,et al.  A new classification for outcomes in illness and injury. , 2005, Hospital medicine.

[5]  A. Beelen,et al.  Beyond disability: perceived participation in people with a chronic disabling condition , 2002, Clinical rehabilitation.

[6]  G. A. van den Bos,et al.  The development of a handicap assessment questionnaire: the Impact on Participation and Autonomy (IPA) , 1999, Clinical rehabilitation.

[7]  H. Meltzer,et al.  The prevalence of disability among adults , 1988 .

[8]  C. Bombardier,et al.  Guidelines for the process of cross-cultural adaptation of self-report measures. , 2000, Spine.

[9]  B. Collopy.  Autonomy in long term care: some crucial distinctions. , 1988, The Gerontologist.

[10]  Douglas G. Altman,et al.  Practical statistics for medical research , 1990 .

[11]  R. Harwood,et al.  Measuring handicap: the London Handicap Scale, a new outcome measure for chronic disease. , 1994, Quality in health care : QHC.

[12]  M. T. J. Buñuales,et al.  La clasificación internacional del funcionamiento de la discapacidad y de la salud (CIF) 2001 , 2002 .

[13]  A. Tennant.  Models of disability: a critical perspective. , 1997, Disability and rehabilitation.

[14]  Mahoney Fi,et al.  FUNCTIONAL EVALUATION: THE BARTHEL INDEX. , 1965 .

[15]  I. Philp,et al.  Care of older people: Maintaining the dignity and autonomy of older people in the healthcare setting , 2001, BMJ : British Medical Journal.

[16]  A. Beelen,et al.  Responsiveness of the Impact on Participation and Autonomy questionnaire. , 2002, Archives of physical medicine and rehabilitation.

[17]  P. Malouf,et al.  Maintaining older people's dignity and autonomy in healthcare settings. Elder abuse is both community and healthcare issue. , 2001, BMJ.

[18]  J. Bornman.  The World Health Organisation's terminology and classification: application to severe disability , 2004, Disability and rehabilitation.

[19]  A. A. Afifi,et al.  Sample size determinations for the two rater kappa statistic , 1988 .

[20]  J. H. Steiger.  Statistically based tests for the number of common factors , 1980 .

[21]  L. Nygård,et al.  Perceptions of participation and predictors of perceived problems with participation in persons with spinal cord injury. , 2005, Journal of rehabilitation medicine.

[22]  P. Bentler,et al.  Comparative fit indexes in structural models. , 1990, Psychological bulletin.

[23]  Reza Vazirinejad,et al.  The ‘Impact on Participation and A utonomy’: acceptability of the English version in a multiple sclerosis outpatient setting , 2003, Multiple sclerosis.

[24]  P. Bentler,et al.  Significance Tests and Goodness of Fit in the Analysis of Covariance Structures , 1980 .

[25]  M. Verkerk.  A care perspective on coercion and autonomy. , 1999, Bioethics.

[26]  R. D. de Haan,et al.  Psychometric properties of the Impact on Participation and Autonomy Questionnaire. , 2001, Archives of physical medicine and rehabilitation.

[27]  D. Streiner,et al.  Health Measurement Scales: A practical guide to thier development and use , 1989 .