Table 2.
Assessment of studies included in this review using the Newcastle-Ottawa Quality Assessment Scale for cohort studies as well as the adapted version for cross-sectional studies
| Selection a | Comparability b | Outcome c | Quality score | |||||
|---|---|---|---|---|---|---|---|---|
| 37 | Representativeness of sample | Sample size | Non-respondents | Ascertainment of exposure | Assessment of outcome | Statistical test | ||
| Anderson [47] | A | A | B | C | A | C | A | 6 |
| Austrom [58] | B | A | A | B | – | C | A | 6 |
| Baker [56] | A | A | A | C | – | C | B | 4 |
| Baker [59] | A | A | A | B | – | C | B | 5 |
| Baker and Hishinuma [74] | B | A | B | B | A/B | C | A | 7 |
| Batchelor [22] | C | B | B | B | – | C | B | 2 |
| Biellauskas [75] | B | B | C | A | A/B | C | A | 6 |
| Brett [51] | B | B | B | B | – | A | A | 5 |
| Burke [76] | C | A | C | B | – | C | B | 3 |
| Chambers [69] | A | A | A | A | – | C | A | 6 |
| Crowson, [6] | A | A | A | A | A | B | – | 7 |
| Davidson [77] | A | A | A | C | – | C | A | 5 |
| Davidson [52] | A | A | C | B | A | C | A | 6 |
| Deitch [48] | A | A | A | B | A/B | C | A | 8 |
| De Santo [78] | A | A | B | B | – | C | B | 4 |
| Dodds [46] | A | A | A | A | A/B | C | A | 9 |
| Donner [79] | D | C | C | C | – | D | B | 0 |
| Draper [40] | A | A | A | B | A | C | A | 7 |
| Draper [80] | A | A | B | A | A/B | C | A | 8 |
| Eagles [30] | A | A | B | B | A | C | B | 5 |
| Evans and Ghosh [43] | A | B | B | A | – | C | A | 5 |
| Farley [39] | A | A | B | A | – | C | B | 4 |
| Fletcher and Schofield [38] | A | A | C | A | A/B | C | A | 8 |
| Florence [81] | A | A | B | B | – | C | B | 4 |
| French [36] | A | A | A | A | A | C | A | 8 |
| French [23] | A | A | A | A | A | C | A | 8 |
| Gee [82] | A | A | B | B | – | C | A | 5 |
| Goldberg [57] | A | A | B | A | – | C | A | 6 |
| Grauer and Campbell [50] | D | B | C | B | – | C | B | 2 |
| Greenfield and Proctor [83] | A | A | B | B | A | C | B | 5 |
| Gregory and Menser [63] | B | A | B | A | A | C | A | 7 |
| Grondin [61] | A | A | B | A | – | C | A | 6 |
| Hall [5] | A | A | B | B | – | C | B | 4 |
| Heponiemi [44] | A | A | B | A | A/B | C | A | 8 |
| Hill [24] | C | A | C | B | – | C | B | 3 |
| Jacobson and Eran [25] | A | A | B | A | A/B | C | A | 8 |
| Jonasson and Kwakwa [84] | A | A | B | B | A | C | B | 5 |
| Joyce [42] | A | A | A | C | A | C | B | 8 |
| Kendell and Pearce [85] | A | A | B | C | – | C | B | 3 |
| Landon [49] | B | A | A | B | A/B | C | A | 8 |
| Lee [77] | A | A | A | B | – | C | B | 5 |
| Lee [87] | B | A | B | B | – | C | A | 5 |
| Luce [7] | A | A | B | A | – | C | A | 6 |
| Moriarty [88] | A | B | B | B | A/B | C | B | 5 |
| McGuirt and McGuirt [89] | B | A | B | B | – | C | B | 4 |
| Mears [41] | A | A | B | B | A | C | A | 6 |
| Meghea and Sunshine [54] | A | A | A | B | A/B | C | A | 8 |
| Newton [26] | C | A | B | A | – | C | B | 4 |
| Onyura [19] | B | A | C | B | – | C | B | 4 |
| Orkin [34] | A | A | B | B | A/B | C | A | 7 |
| Peisah [45] | C | A | C | A | – | C | B | 4 |
| Pit and Hansen [16] | B | A | B | A | A/B | C | A | 8 |
| Quandango [27] | C | A | B | B | – | C | B | 3 |
| Rayburn [31] | A | A | B | B | – | B | B | 5 |
| Reuben and Silliman [47] | A | A | A | B | A/B | C | A | 8 |
| Ritternhouse [33] | A | A | A | B | A/B | B | A | 9 |
| Rowe [90] | A | A | B | C | – | C | B | 3 |
| Shanafelt [53] | A | A | A | A | A/B | C | A | 9 |
| Sibbald [32] | A | A | A | A | A/B | A | A | 9 |
| Silver [29] | B | A | B | B | – | C | B | 4 |
| Smith [91] | A | A | C | A | – | C | B | 5 |
| Sutinen [35] | A | A | A | A | A/B | C | A | 8 |
| Van Greuningen [17] | A | A | B | A | – | C | A | 7 |
| Wakeford [18] | A | A | C | B | – | C | B | 4 |
“–”, not reported.
Wells, G.A.; Shea, B.; O’Connell, D.; Peterson, J.; Welch, V.; Losos, M.; Tugwell, P. The Newcastle-Ottawa Scale (NOS) for assessing the quality of nonrandomized studies in meta-analyses. Available online: http://www.ohri.ca/programs/clinical_epidemiology/oxford.asp
aSelection (5 points in total): (1) Representativeness of the sample: A, truly representative of the average in the target population (1 point); B, somewhat representative of the average in the target population (1 point); C, selected group of users (no points); D, no description of the sampling strategy (no points). (2) Sample size: A, justified and satisfactory (1 point); B, not justified (no points). (3) Non-respondents: A, comparability between respondents and non-respondents characteristics is established, and the response rate is satisfactory (1 point); B, the response rate is unsatisfactory, or the comparability between respondents and non-respondents is unsatisfactory (no points); C, no description of the response rate or the characteristics of the responders and the non-responders (no points). (4) Ascertainment of the exposure: A, validated measurement tool (2 points); B, non-validated measurement tool, but the tool is available or described (1 point); C, no description of the measurement tool (no points).
bComparability (2 points in total): (1) Confounding factors are controlled: A, the study controls for the most important factor (1 point); B, the study control for any additional factor (1 point).
c Outcome (3 points in total): (1) Assessment of the outcome: A, independent blind assessment (2 points); B, record linkage (2 points); C, self-report (1 point); D, no description (no points). (2) Statistical test: A, the statistical test used to analyze the data is clearly described and appropriate, and the measurement of the association is presented, including confidence intervals and the probability level (P value) (1 point); B, the statistical test is not appropriate, not described or incomplete (no points).