Validität und Reliabilität der Deutschen fassung des SF-36 bei patienten mit amyotropher lateralsklerose

Objectives: To evaluate response rate, data quality, score reliability and scaling assumptions of the 36 item Short Form Health Survey (SF-36) in a survey of Amyotrophic Lateral Sclerosis (ALS) patients recruited into the ALS Health Profile Study (ALS-HPS) in Germany. Design: A questionnaire based survey of patients diagnosed with ALS in Germany. Sample: Patients presenting at neurological clinics throughout Germany for treatment of their condition were asked to take part in the survey. Results: 355 patients were recruited, and responses were obtained from 291 (82.0%). Scores on six of the eight dimensions of the SF-36 showed high internal consistency. Energy/Vitality and General Health dimensions were the two exceptions. Items correlated more highly with their own (corrected) scale score than with other scale scores. However, on two dimensions (Role-Physical and Role-Emotional) there were high levels of missing data, and substantial floor and ceiling effects. The two factor model of underlying constructs of physical and emotional health for the SF-36 suggested by its developers was not supported in this patient group. Conclusion: The SF-36 appears to provide reliable information across most dimensions in ALS. In general, there were high levels of item completeness and a good spread of scores, but this was not true for the role functioning dimensions. The underlying two factor model for the SF-36 was not supported. The implications of these findings for measuring health status in this patient group are discussed.