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Table 1 The Newcastle-Ottawa Scale (NOS) for assessing the quality of case controlled studies in meta-analyses

From: Effect of buried vs. exposed Kirschner wire osteosynthesis on phalangeal, metacarpal and distal radial fractures: A systematic review and meta-analysis

SelectionComparabilityExposure
1) Is the case definition adequate?1) Comparability of cases and controls on the basis of the design or analysis1) Ascertainment of exposure
 a) yes, with independent validation* a) secure record (e.g.: surgical records)*
 b) yes, e.g. record linkage or based on self reports b) structured interview where blind to case/control status*
 c) no description a) study controls for __ (Select
2) Representativeness of the casesthe most important factor.)* c) interview not blinded to case/control status
 a) consecutive or obviously representative series b) study controls for any additional factor (This criteria could be modified to indicate specific control for a second important factor.)*
of cases* d) written self report or medical record only
 b) potential for selection biases or not stated
3) Selection of Controls e) no description
 a) community controls*2) Same method of ascertainment for cases and controls
 b) hospital controls
 c) no description a) yes*
 b) no
4) Definition of Controls3) Non-Response rate
 a) no history of disease (endpoint)* a) same rate for both groups*
 b) no description of source b) non respondents described
 c) rate different and no designation
  1. Note: A study can be awarded a maximum of one star for each numbered item within the Selection and Exposure categories. A maximum of two stars can be given for Comparability". The "*" means one star
  2. From GA. W, B. S, D. OC, et al. The Newcastle-Ottawa Scale (NOS) for assessing the quality of nonrandomised studies in meta-analyses