There was no consistent relationship with factors such as disease-specific or generic instrument or the number of response options .
Negative changes were not associated with larger ESs .
Population -based estimation procedures and brief follow-up were associated with smaller ESs , and acute conditions with larger ESs .
Background .
A number of studies have computed the minimally important difference ( MID ) for health-related quality of life instruments .
To determine whether there is consistency in the magnitude of MID estimates from different instruments .
Structured exercise improves physical functioning in women with stages I and II breast cancer: results of a randomized controlled trial.
PURPOSE Self-directed and supervised exercise were compared with usual care in a clinical trial design ed to evaluate the effect of structured exercise on physical functioning and other dimensions of health-related quality of life in women with stages I and II breast cancer . PATIENTS AND METHODS One hundred twenty-three women with stages I and II breast cancer completed baseline evaluations of generic and disease- and site-specific health-related quality of life , aerobic capacity , and body weight . Participants were r and omly allocated to one of three intervention groups : usual care ( control group ) , self-directed exercise , or supervised exercise .  Quality of life , aerobic capacity , and body weight measures were repeated at 26 weeks . The primary outcome was the change in the Short Form-36 physical functioning scale between baseline and 26 weeks . RESULTS Physical functioning in the control group decreased by 4.1 points , whereas it increased by 5.7 points and 2.2 points in the self-directed and supervised exercise groups , respectively ( P = .04 ) . Post hoc analysis showed a moderately large ( and clinical ly important ) difference between the self-directed and control groups ( 9.8 points ; P = .01 ) and a more modest difference between the supervised and control groups ( 6.3 points ; P = .09 ) . No significant differences between groups were observed for changes in quality of life scores . In a secondary analysis of participants stratified by type of adjuvant therapy , supervised exercise improved aerobic capacity ( + 3.5 mL/kg/min ; P = .01 ) and reduced body weight ( -4.8 kg ; P < .05 ) compared with usual care only in participants not receiving chemotherapy . CONCLUSION Physical exercise can blunt some of the negative side effects of breast cancer treatment , including reduced physical functioning .  Self-directed exercise is an effective way to improve physical functioning compared with usual care . In participants not receiving chemotherapy  , supervised exercise may increase aerobic capacity and reduce body weight compared with usual care
There was no consistent relationship with factors such as disease-specific or generic instrument or the number of response options .
Negative changes were not associated with larger ESs .
Population -based estimation procedures and brief follow-up were associated with smaller ESs , and acute conditions with larger ESs .
Background .
A number of studies have computed the minimally important difference ( MID ) for health-related quality of life instruments .
To determine whether there is consistency in the magnitude of MID estimates from different instruments .