. Our sensitivity analyses suggested that the overall estimates were not materially altered by changing the pooling models (random-effects model, OR 0.00, 00% CI 0.00--0.00; fixed-effects model, OR 0.00, 00% CI 0.00--0.00) and were not materially altered when an individual study was omitted from the sequence, with a range of 0.00 (00% CI 0.00--0.00) to 0.00 (00% CI 0.00--0.00)