Development and Validation of a Fall Questionnaire for Patients with Parkinson's Disease

Abstract

Background In Parkinson's disease, postural instability and falls are of particular socioeconomic relevance. Although effective fall prevention and the prophylaxis of fall‐related injuries depend on low‐threshold symptom monitoring, validated instruments are lacking. Objectives To develop a self‐report questionnaire for the assessment of falls, near falls, fear of falling, fall‐related injuries, and causes of falls for patients with Parkinson's disease (PwPD). Methods A pool of potential items was generated from a literature review and by discussion in an expert panel. The first version of the Dresden Fall Questionnaire (DREFAQ) was tested in a group of German‐speaking movement disorder specialists as well as PwPD. The resulting 5‐item questionnaire was assessed in a validation cohort of 36 PwPD who documented fall events and near‐fall events in a calendar for 3 months and completed the DREFAQ at the end of the study. The questionnaire was subsequently used in a separate cohort of 46 PwPD to determine test–retest reliability and confirm the factor structure. Results The DREFAQ showed good internal consistency (Cronbach's α = 0.84) and good test–retest reliability (intraclass correlation coefficient, 0.76; 95% confidence interval, 0.60–0.86). The total DREFAQ score showed good concurrent validity with fall events (Spearman's ρ = 0.82) and near‐fall events (Spearman's ρ = 0.78) as determined by fall and near‐fall diaries. Factor analysis revealed a 2‐factor structure composed of near falls with fear of falling and severe falls with injuries. Conclusions The DREFAQ is a reliable and valid 5‐item questionnaire for determining the incidence of falls, near falls, fear of falling, fall‐related injuries, and causes of falls in PwPD.