The Center for Evidence-based Practice at Penn Medicine reported a modified Newcastle-Ottawa scale for the evaluation of non-randomized controlled studies.


(1) study population: items 1 and 2

(2) study validity: items 3, 4, 5

(3) confoounders: items 6, 7, 8



(1) study groups derived from similar populations

(2) study groups show comparable attrition

(3) exposure measure valid

(4) outcome measure valid

(5) investigators blinded to the endpoint assessment

(6) potential confounders identified

(7) potential confounders are statistically adjusted

(8) no obvious conflicts of interest with funding sources disclosed


Each item is answered Yes or No, with Yes responses considered appropriate.

To read more or access our algorithms and calculators, please log in or register.