Consistent evidence was found for the predictive value of pain intensity ( more pain-- > worse outcome ) , several work-related parameters ( e.g. , high satisfaction-- > better outcome ) , and coping style ( less active coping-- > better outcome ) .
Other sociodemographic and physical variables consistently lacked predictive value .
No consistent evidence was found for other psychological variables .
CONCLUSIONS It is impossible to define a generic set of predictors of outcome of multidisciplinary rehabilitation and back schools for patients with chronic low back pain because the review ed studies were descriptive or exploratory in nature , and most predictors were only studied once .
Nevertheless , for several predictors , consistent evidence was found .
OBJECTIVE To determine predictors of outcome of multidisciplinary rehabilitation-or back school treatment  for patients with chronic low back pain .
SUMMARY OF BACKGROUND DATA Numerous review s have been performed to gain insight into which patients benefit from which treatment .
However , no review has systematic ally focused on predictors from multiple domains ( i.e. , sociodemographic , physical , and psychological ) , or on treatment outcome measured as activity limitation or participation restriction .
[The practice of systematic reviews. V. Heterogeneity between studies and subgroup analysis].
Meta- analysis comprises the analysis of the data of similar studies gathered in a systematic review . If the results of the studies differ ( strongly ) , this is called heterogeneity . Possible causes of heterogeneity are : a wrong choice of type of measure of treatment effect , differences of method ological quality between studies , or real differences between studies . Heterogeneity between studies can be assessed by thorough examination of the differences between study characteristics in combination with a visual inspection of the degree of overlap of the confidence intervals of the estimates of effect of the different studies . By applying the r and om effects model for pooling , ( non- systematic ) heterogeneity between studies can be addressed . In case of heterogeneity between studies , sources of heterogeneity should be explored by means of subgroup analysis according to strict , present criteria . Subgroup analysis should address subgroups of patients within studies
Consistent evidence was found for the predictive value of pain intensity ( more pain-- > worse outcome ) , several work-related parameters ( e.g. , high satisfaction-- > better outcome ) , and coping style ( less active coping-- > better outcome ) .
Other sociodemographic and physical variables consistently lacked predictive value .
No consistent evidence was found for other psychological variables .
CONCLUSIONS It is impossible to define a generic set of predictors of outcome of multidisciplinary rehabilitation and back schools for patients with chronic low back pain because the review ed studies were descriptive or exploratory in nature , and most predictors were only studied once .
Nevertheless , for several predictors , consistent evidence was found .
OBJECTIVE To determine predictors of outcome of multidisciplinary rehabilitation-or back school treatment  for patients with chronic low back pain .
SUMMARY OF BACKGROUND DATA Numerous review s have been performed to gain insight into which patients benefit from which treatment .
However , no review has systematic ally focused on predictors from multiple domains ( i.e. , sociodemographic , physical , and psychological ) , or on treatment outcome measured as activity limitation or participation restriction .