Exploration for sources of heterogeneity.

Relative covariate effects (singly- or multiply-adjusted) on diagnostic Odds Ratios for dipstick diagnosis of egg-positive urine among all included studies (N = 94).aA best fit reduced multivariable adjusted model was selected by stepwise backward removal of non-significant cofactors from a full model containing all covariates. The final working model presented here was selected when all variables in the model were either statistically significant or biologically plausible and marginally significant.bThe dashes indicate insufficient data in this category for an estimate.