Validation of the revised Amyotrophic Lateral Sclerosis Functional Rating Scale in Poland and its reliability in conditions of the medical experiment

INTRODUCTION: Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised (ALSFRS-R) is a basic tool for monitoring disease progression in amyotrophic lateral sclerosis (ALS). This study analyses the reliability of the Polish version of the ALSFRS-R as a tool to assess the health condition of patients with ALS and presents experience related to the use of this tool in monitoring the effects of experimental medical therapy. MATERIALS AND METHODS: The scale questionnaire was translated using the cross-translation method. The final tool was used by researcher, who was conducting the interview directly by telephone with patients and their caregivers and additionally compared with neurologopedic measurement. The health status of 60 patients was assessed between 4 and 7 times, which gives a total of 327 observations. Mean patient’s age was 57.5 ± 8.6. The division by sex was 23/35 (female/male). Patients’ health status and severity of symptoms varied. Statistical analysis was performed using explanatory factor analysis and Cronbach’s alpha. RESULT: Validation of the Polish version of the ALSFRS-R supports the reliability and internal consistency of scale. The scale proved also to be a proper tool for monitoring the course of the experimental medical therapy for patients with ALS. However, a qualitative evaluation revealed certain weaknesses of the scale, resulting from a different understanding of the functional assessment by the patient and by the medical specialist and cultural differences. DISCUSSION: Although ALSFRS-R is a reliable enough for monitoring patient health, it seems reasonable to pay attention to some difficult points of the questionnaire and its improvement. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s10072-020-04565-5) contains supplementary material, which is available to authorized users.