Table 1 Criteria list for the methodological quality assessment of the studies and definitions of the criteria
Effect evaluations | ||
|---|---|---|
Internal validity/study design | ||
V1 | Randomization procedure | Positive if a random (unpredictable) assignment procedure sequence of subjects to the study groups was used and if there was a clear description of the procedure and adequate performance of the randomization |
V2 | Similarity of companies | Positive if they controlled for variability in included companies |
V3 | Similarity of study groups | Positive if the study groups were similar at the beginning of the study |
V4 | Dropout | Positive if the percentage of dropouts during the study period did not exceed 20% for short-term follow-up (≤ 3 months) or 30% for long-term follow-up (> 3 months) and adequately described |
V5 | Timing of outcome measurement | Positive if timing of outcome assessment was identical for intervention and control groups and for all important outcomes assessments. |
V6 | Blinding | Positive if the person performing the assessments was blinded to the group assignment |
V7 | Co-interventions | Positive if co-interventions were avoided or comparable. |
V8 | Outcome | Positive when data on outcome was selected with standardized methods of acceptable quality |
Descriptive criteria | ||
D1 | Eligibility criteria (in- and exclusion criteria) | Positive if in- and exclusion criteria of participants were specified |
D2 | Baseline characteristics | Positive if an adequate description of the study groups was given for demographic variables: gender, age, type of work, hours a week working, education level, baseline main outcome measures |
D3 | Company characteristics | Positive if an adequate description of the included companies was given (type of industry, organizational characteristics) |
D4 | Intervention | Positive if an adequate description was given of the interventions(s): number of intervention aspects, type of interventions, frequency of sessions, intensity of intervention(s) |
D5 | Follow-up | Positive if a follow-up of 6 months or longer was described. |
Analysis | ||
A1 | Sample size | Positive if an adequate sample size calculation was described |
A2 | Confounders | Positive if the analysis controlled for potential confounders |
A3 | Intention to treat | Positive if the intervention and control subjects were analyzed according to the group belonging to their initial assignment, irrespective of non-compliance and co-interventions. |
Process evaluations | ||
T1 | Model used for evaluation | Positive if a theoretical framework for the evaluation was used and adequately described. |
T2 | Level of evaluation | Positive if implementation was evaluated on 2 or more levels (i.e. macro, meso, micro) |
T3 | Definition of outcome measure (process components) | Positive if the definition of the outcome measures (process variables and barriers and/or facilitators) were accurately described |
T4 | Reported process variables | a. Positive if four or more process evaluation variables are evaluated (in process evaluation) |
b. Positive if barriers or facilitators on 1 or more levels are presented | ||
T5 | Data collection | Positive if 2 or more techniques for data collection were used (triangulation). |
T6 | Timing of data collection | Positive if measurements of barriers and/or facilitators were performed pre-, during and after implementation. |
T7 | Quantitative outcome measures | Positive if data on quantitative outcome was selected with methods of acceptable quality and data on multiple process components was measured. |
T8 | Qualitative data | a. Positive if study design for qualitative data (theoretical framework, participant selection, setting, data collection) were adequately described |
b. Positive if qualitative data was analyzed by two researchers. | ||
T9 | Outcome related to implementation of intervention | Positive if outcomes (barriers and/or facilitators) are related to the quality of implementation |