Physical Activity and Quality of Life in Severely Obese Adults during a Two-Year Lifestyle Intervention Programme

Table 4

Mean and standard deviation of quality of life outcomes during the two-year lifestyle intervention for severely obese adults.

					Population norm
SF-36^a
Physical component summary	45.3 (9.6)	51.2 (7.3)	50.5 (7.8)	49.9 (7.6)	49.0
Effect size	−0.39	0.30	0.19	0.12
Mental component summary	48.4 (10.2)	54.0 (7.7)	48.6 (12.8)	47.8 (10.7)	49.0
Effect size	−0.06	0.65	−0.03	−0.11
Obesity-related problems^b					n/a
	44.6 (26.3)	36.7 (25.0)	31.8 (28.0)	29.7 (24.4)
Life satisfaction^c					n/a
	4.6 (0.9)	5.5 (1.0)	5.1 (0.9)	4.8 (0.9)

: before the intervention; : after six weeks; : year one; : year two.
^aScale 0–100: higher scores represent better quality of life, Medical Outcomes Study Short-Form 36 Health Survey (SF 36). The SF-36 data for the norm population () are adjusted for gender and age [39] and presented as means. Effect sizes for differences between the study participants and the norm population were calculated by subtracting the mean score of the population norm from the mean score of the study participants divided by the SD of the latter. They were judged against the standard criteria proposed by Cohen: trivial (<0.2), small (0.2 to <0.5), moderate (0.5 to <0.8), and large (≥0.8) [41].
^bScale 0–100: higher scores represent more obesity-related problems, Obesity-Related Problems scale.
^cScale 1–7: higher scores represent better life satisfaction.