To compare results on the 40-item Amyotrophic Lateral Sclerosis Assessment Questionnaire (ALSAQ-40) with those gained on the short-form five-item Amyotrophic Lateral Sclerosis Assessment Questionnaire (ALSAQ-5) in a longitudinal study.Design
Postal survey. Copies of the ALSAQ-40 which incorporates the five items of the ALSAQ-5, were completed on two occasions. Respondents were also asked to indicate how much change they had experienced since baseline on each of the five domains of the questionnaire.Setting
The database of all patient members of the Motor Neurone Disease Association for England, Wales and Northern Ireland.Subjects
Nine hundred and twenty-seven patient members returned questionnaires at baseline, and 764 completed questionnaires at both baseline and follow-up.Results
Results on the five dimensions of the ALSAQ-40 and ALSAQ-5 were found to be highly correlated, and 95% confidence intervals on mean scores were found to overlap for each dimension. The instruments both provide a similar picture of change in terms of their responsiveness. For example, effect sizes were calculated for patients who claimed their health had deteriorated a little since baseline, and gave almost identical results (e.g. for the Physical functioning domain effect sizes of 0.12 and 0.11 were found on the long and short measures respectively).Conclusions
Results suggests that the ALSAQ-5 provides similar results to the ALSAQ-40 yet with considerable economy. In instances where a very brief health status measure is required then the ALSAQ-5 may be the instrument of choice.