Table A1
Systematic review of prognostic cohort studies on duration of sick leave due to LBP in the acute phase
| Prognostic cohort studies on duration of sick leave due to LBP in the acute phase | ||
|---|---|---|
| +, positive; −, negative; ?, not clear. | ||
| Study population | ||
| a | Inception cohort: positive if patients were identified at an early uniform point (inception cohort) in the course of their sick leave due to low back pain). In this review <6 weeks after start of sick leave. | +/−/? |
| b | Description of inclusion and exclusion criteria: positive if criteria were formulated for: age, duration of symptoms, duration of sick leave, co-morbidity | +/−/? |
| c | Description of study population: positive if described in what setting the patients are recruited (i.e. general practice, hospital, occupational setting) | +/−/? |
| Response | ||
| d | Response: positive if the response ⩾75% | +/−/? |
| e | Information on non-responders versus responders: positive if information presented about patient/disease characteristics of responders/non-responders or no selective response | +/−/? |
| + = no selective response, information given; − = selective response, information given; ? = not clear | ||
| Follow up (extent and length) | ||
| f | Positive if prospective design was used, also positive in case of a retrospective cohort and determinants are measured before outcome. | +/−/? |
| g | Positive if the follow up period was at least 12 months | +/−/? |
| h | Positive if total number of drop-outs/loss to follow up <20% on the last moment of follow up | +/−/? |
| i | Information completers versus loss to follow-up/drop-outs: positive if demographic/clinical information (patient/disease characteristics such as age, sex, and other potential prognostic predictors) was presented for completers and those lost to follow up/drop-outs at the main moment of outcome measurement, or no drop-outs/loss to follow up | +/−/? |
| Loss to follow-up/drop-outs: all patients of the assembled cohort minus the number of patients at the main health status measurement for the main outcome measure, divided by all patients of the assembled cohort | ||
| + = no selective follow up, information given; − = selective follow up, information given; ? = not clear | ||
| Outcome | ||
| j | Definition of main outcome: return to work | +/−/? |
| Prognostic factors | ||
| k | Standardised assessment of patient characteristics and potential clinical prognostic factor(s): positive if standardised questionnaires or objective measurements were used at baseline of at least 4 of the following 7 potential prognostic factors: | +/−/? |
| (a) age; (b) sex; (c) pain; (d) functional status; (e) duration of complaints; (f) back complaints; (g) physical workload | ||
| l | Standardised assessment of potential psychosocial prognostic factor(s): positive if standardised questionnaires or objective measurements were used at baseline of at least 1 of the following 6 potential prognostic factors: | +/−/? |
| (a) depression; (b) somatisation; (c) distress; (d) fear and avoidance; (e) coping strategies; (f) psychosocial work related factors (social support, job decision latitude) | ||
| Data presentation | ||
| m | Frequencies given of main outcome measure (return to work): positive if frequency, percentage or mean, median (interquartile range) and standard deviation/CI are reported of the outcome measures | +/−/? |
| n | Frequencies of all prognostic factors: positive if frequency, percentage or mean, median (interquartile range) and standard deviation/CI are reported of all prognostic factors | +/−/? |
| o | Appropriate analysis techniques: positive if univariate crude estimates are provided | +/−/? |
| Positive in case hazard ratios, odds ratios, relative risks, or relative risk ratios are presented | ||
| Negative in case correlations are reported | ||
| p | Multivariate prognostic model is presented: positive if attempt is made to determine a set of prognostic factors with the highest prognostic value. >Positive if a manual forward stepwise procedure was used (pin <0.05; pout ⩾0.10) | +/−/? |
| Negative in case of an analysis based on an automated forward or stepwise procedure | ||
| q | Sufficient numbers: positive if the number of cases in the multivariate analysis was at least ten times the number of independent variables in the analysis | +/−/? |
