Table 4.
Methodological quality of the included studies
| Quantitative study (in order of quality) | Design | Population | Control group | Outcomes, instruments | Data analysis | Scorea |
|---|---|---|---|---|---|---|
| Brouwers et al. [11] | ++ | ++ | ++ | + | + | 8 (Good) |
| van der Feldtz-Cornelis et al. [12] | ++ | ++ | ++ | + | + | 8 (Good) |
| Mortelmans et al. [13] | ++ | ++ | ++ | + | + | 8 (Good) |
| Bogefeldt et al. [18] | ++ | ++ | + | + | + | 7 (Good) |
| Bültmann et al. [20] | ++ | ++ | ++ | + | −+ | 7 (Good) |
| Fleten and Johnsen [24] | ++ | ++ | + | + | + | 7 (Good) |
| van der Klink et al. [16] | ++ | ++ | + | + | + | 7 (Good) |
| Arnetz et al. [19] | ++ | ++ | + | + | −+ | 6 (Good) |
| Bakker et al. [29] | ++ | + | + | + | + | 6 (Good) |
| Drews et al. [32] | + | ++ | + | + | + | 6 (Good) |
| Hagen et al. [30] | ++ | ++ | + | + | −+ | 6 (Good) |
| Nystuen and Hagen [31] | ++ | ++ | + | + | −+ | 6 (Good) |
| Braathen et al. [25] | + | ++ | + | + | −+ | 5 (Moderate) |
| Marhold et al. [23] | ++ | −+ | + | + | + | 5 (Moderate) |
| Grossi and Santell [22] | ++ | −+ | + | + | −+ | 4 (Moderate) |
| Godges et al. [26] | + | + | −+ | + | −+ | 3 (Moderate) |
| Matheson and Brophy [21] | −+ | ++ | −+ | + | −+ | 3 (Moderate) |
| Weiler et al. [15] | + | −+ | −+ | + | + | 3 (Moderate) |
| Review (in order of quality) | Research question | Search | Quality evaluation | Data extraction | Description methods original studies | Meta-analysis | Scorea |
|---|---|---|---|---|---|---|---|
| van Oostrom et al. [14] | ++ | ++ | ++ | ++ | ++ | ++ | 12 (Very good) |
| Carroll et al. [17] | ++ | ++ | + | ++ | ++ | ++ | 11 (Very good) |
| Meijer et al. [7] | + | + | + | − | ++ | ++ | 6 (Good) |
| Norlund et al. [27] | + | + | −+ | − | ++ | ++ | 5 (Good) |
| Tveito et al. [28] | + | − | ++ | − | + | − | 1 (Insufficient) |
− = Minus one, insufficient; −+ = zero, neutral/sufficient; + = one, good; ++ = two, very good. A criteria is also ranked with a −+ in case it was inapplicable to the article or in case it cannot be identified based on the text in the article
Methodological quality score of quantitative studies: −1 to 2 (insufficient), 3–5 (moderate), 6–8 (good), 9–11 (very good). Methodological quality of systematic reviews: −4 to 0 (insufficient), 1–4 (moderate), 5–8 (good), 9–12 (very good)
Methodological quality ranges: quantitative studies from −1 to 11, systematic literature reviews ranges from −4 to 12. Mean scores are calculated when a criteria existed of multiple sub criteria. These mean scores were taken into account in the overall calculation of quality
aFinal quality scores are calculated by adding up all pluses and subtracting all minuses