Table 4: NOS for cohort studies.

StudySelectionComparabilityOutcomeSum of score

Cho et al. [16]●●●●●●●7
Walline et al. [17]●●●●●6
Kakita et al. [18]●●●●●●●●●9
Hiraoka et al. [20]●●●●●●●●8
Santodomingo-Rubido  et  al. [21, 24]●●●●●●●●●9
Chen et al. [23]●●●●●●●●8

NOS generates a quality score, maximum of 9 points, based on assessment of 3 study characteristics: patient selection methodology (maximum of 4 points), comparability of the study groups (maximum of 2 points), and outcomes measures (maximum of 3 points). The total score ranged from 0 (bad) to 9 (good).