Six minutes walk test for individuals with schizophrenia

Abstract

Purpose: The six-minute walk test (6MWT) is a sub-maximal exercise test measuring the distance that a patient can walk quickly in a period of 6 minutes (6MWD). The objectives of this systematic review are to evaluate the 6MWT's suitability for measuring the impact of an intervention, to compare the 6MWD walked by patients with schizophrenia with data for the general population or matched controls, to identify the determinants of 6MWD and to examine the measurement properties and quality procedures of the 6MWT.

Methods: Using five databases, we performed a systematic review of full-text articles published through August 2013.

Results: Sixteen studies met our selection criteria. The assessment of the 6MWT's suitability for measuring the impact of interventions was not made because none of the interventional studies reported a significant increase in 6MWD. The distance walked by adults with schizophrenia seemed generally shorter than that walked by healthy adults. Mean 6MWDs ranged from 421 m to 648 m in the included studies. The 6MWD is usually negatively associated with a higher Body Mass Index, increased cigarette consumption, higher doses of antipsychotic medication and lower physical self-worth in individuals with schizophrenia. The 6MWT demonstrates high reliability. To date, however, its criterion validity has not been investigated. In spite of existing guidelines, the test procedures used in the studies reviewed varied significantly.

Conclusions: Future physical health monitoring recommendations for patients with schizophrenia should include the 6MWT. Future studies should investigate its predictive role and continue to assess its measurement properties.

Implications for rehabilitation: The Six-Minute Walk Test reliably assesses the functional exercise capacity in patients with schizophrenia. The impact of therapeutic interventions on patients, as measured by the 6MWT, cannot be confirmed. Clinicians should take into account overweight, antipsychotic medication use and the physical self-perception when considering the functional exercise capacity in schizophrenia. Clinicians should follow International standards such as these of the American Thoracic Society when using the Six-Minute Walk Test in patients with severe mental illnesses.

Keywords: 6-minute walk test; exercise; functional capacity; physical health; schizophrenia.