Table 1.
Newscastle‐Ottawa Quality Assessment Scale
| Scales for quality assessment criteria | Stars |
|---|---|
| Selection | |
| (1) Is the case definition adequate? | |
| a) Yes, with independent validation | ☆ |
| b) Yes, e.g. record linkage or based on self reports | |
| c) No description | |
| (2) Representativeness of the cases | |
| a) Consecutive or obviously representative series of cases | ☆ |
| b) Potential for selection biases or not stated | |
| (3) Selection of Controls | |
| a) Community controls | ☆ |
| b) Hospital controls | |
| c) No description | |
| (4) Definition of Controls | |
| a) No history of disease (endpoint) | ☆ |
| b) No description of source | |
| Comparability | |
| (1) Comparability of cases and controls on the basis of the design or analysis | |
| a) Study controls for _______________ (Select the most important factor.) | ☆ |
| b) Study controls for any additional factor (This criteria could be modified to indicate specific control for a second important factor.) | ☆ |
| Exposure | |
| (1) Ascertainment of exposure | |
| a) Secure record (e.g. surgical records) | ☆ |
| b) Structured interview where blind to case/control status | ☆ |
| d) Written self report or medical record only | |
| e) No description | |
| (2) Same method of ascertainment for cases and controls | |
| a) Yes | ☆ |
| b) No | |
| (3) Non‐Response rate | |
| a) Same rate for both groups | ☆ |
| b) Non respondents described | |
| c) Rate different and no designation | |