Reliability, minimal detectable changes, practice effects and correlates of the 6-min walk test in patients with schizophrenia

We examined the reproducibility of the 6-min walk test (6MWT) in patients with schizophrenia. Secondary aims were to assess minimal detectable changes and practice effects of the 6MWT and the presence of clinical conditions that might interfere. From 71 patients with schizophrenia two trials of the 6MWT, administered within 3 days, were analysed. The intraclass correlation coefficient between the two tests was 0.96. The minimal detectable change was 56.2 m for men and 50.2 m for women. Body mass index, daily antipsychotic dose, negative and depressive symptoms, resting heart rate, age, smoking behavior and different musculoskeletal complaints were all significantly associated with the distance walked. The 6MWT can be recommended for evaluating the functional exercise capacity in patients with schizophrenia. Some practice effect could however not be excluded.