Table 1 Newcastle - Ottawa quality assessment scale case–control studies
Criteria | Score |
|---|---|
Selection | |
1) Is the case definition adequate? | |
a) yes, with independent validation | ☆ |
b) yes, eg 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 the most important factor | ☆ |
b) study controls for any additional factor | ☆ |
Exposure | |
1) Ascertainment of exposure | |
a) secure record (eg surgical records) | ☆ |
b) structured interview where blind to case/control status | ☆ |
c) interview not blinded 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 |