Table II.
Newcastle-Ottawa scale (NOS) for the assessment of the quality of case control studies (adjusted to the criteria of the present systematic review).
| NOS scale | Studies presented according to fulfilled criterion (★); Author, year (Ref.) | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| A, Selection (maximum 4) | Control group characteristics | Menning et al, 2016 (26) | Andreano et al, 2011 (27) | Calvio et al, 2010 (28) | Debess et al, 2009 (29) | Levkovich et al, 2018 (30) | Henneghan et al, 2018 (31) | Kamena et al, 2017 (32) | Hermenlik et al, 2017 (33) |
| 1. Case definition adequate | With independent validation | ★ | ★ | ★ | ★ | ★ | ★ | ||
| 2. Representativeness of the cases | Consecutive or obviously representative series of cases | ★ | ★ | ★ | ★ | ★ | ★ | ★ | ★ |
| 3. Selection of controls | Community controls | ★ | ★ | ★ | |||||
| 4. Definition of control | No history of breast cancer | ★ | ★ | ★ | ★ | ||||
| B, Comparability (maximum 2) | Control group characteristics | Menning et al, 2016 (26) | Andreano et al, 2011 (27) | Calvio et al, 2010 (28) | Debess et al, 2009 (29) | Levkovich et al, 2018 (30) | Henneghan et al, 2018 (31) | Kamena et al, 2017 (32) | Hermenlik et al, 2017 (33) |
| 1. Comparability of cases and controls on the basis of the design or analysis | Study controls matched for age and sex | ★ | ★ | ★ | ★ | ★ | ★ | ★ | ★ |
| 2. Study controls for any additional factor | Study controls matched for age of menarche, menopausal status, age at any childbirth, lifetime estrogen exposure, working status, educational status, marital status, premorbid IQ, income, current occupation, primary occupation, medication for other physical or psychiatric diseases and/or contraceptives use etc. | ★ | ★ | ★ | ★ | ★ | ★ | ★ | ★ |
| C. Exposure (maximum 3) | Control group characteristics | Menning et al, 2016 (26) | Andreano et al, 2011 (27) | Calvio et al, 2010 (28) | Debess et al, 2009 (29) | Levkovich et al, 2018 (30) | Henneghan et al, 2018 (31) | Kamena et al, 2017 (32) | Hermenlik et al, 2017 (33) |
| 1. Ascertainment of exposure | Secure record or structured interview where blind to case/control status | ★ | ★ | ||||||
| 2. Same method cases and controls | Yes | ★ | ★ | ★ | |||||
| 3. Non-response rate | Same rate for both groups | ★ | ★ | – | |||||
| Total quality score (maximum 9) | 6 | 4 | 6 | 8 | 5 | 4 | 5 | 7 | |
Each star symbol indicates whether the individual criterion within the subsection was fulfilled in each study.