Measuring physical activity levels in hospitalized patients: a comparison between behavioural mapping and data from an accelerometer.

OBJECTIVE:: To investigate the level of agreement of the behavioural mapping method with an accelerometer to measure physical activity of hospitalized patients.

DESIGN:: A prospective single-centre observational study.

SETTING:: A university medical centre in the Netherlands.

SUBJECTS:: Patients admitted to the hospital.

MAIN MEASURES:: Physical activity of participants was measured for one day from 9 AM to 4 PM with the behavioural mapping method and an accelerometer simultaneously. The level of agreement between the percentages spent lying, sitting and moving from both measures was evaluated using the Bland-Altman method and by calculating Intraclass Correlation Coefficients.

RESULTS:: In total, 30 patients were included. Mean (±SD) age was 63.0 (16.8) years and the majority of patients were men ( n = 18). The mean percentage of time (SD) spent lying was 47.2 (23.3) and 49.7 (29.8); sitting 42.6 (20.5) and 40.0 (26.2); and active 10.2 (6.1) and 10.3 (8.3) according to the accelerometer and observations, respectively. The Intraclass Correlation Coefficient and mean difference (SD) between the two measures were 0.852 and -2.56 (19.33) for lying; 0.836 and 2.60 (17.72) for sitting; and 0.782 and -0.065 (6.23) for moving. The mean difference between the two measures is small (⩽2.6%) for all three physical activity levels. On patient level, the variation between both measures is large with differences above and below the mean of ⩾20% being common.

CONCLUSION:: The overall level of agreement between the behavioural mapping method and an accelerometer to identify the physical activity levels 'lying', 'sitting' and 'moving' of hospitalized patients is reasonable.