Comparison of laboratory results and pain perception in self-sampled capillary blood versus venous blood sampling: a systematic review and meta-analysis.

Blood sampling is an essential part of medical diagnostics and treatment. Recent advances in capillary blood self-collection (BSC) devices offer promising alternatives to traditional venipuncture. However, the concordance between laboratory results from self-collected capillary samples and the gold standard venous collection requires systematic evaluation before clinical implementation. We conducted a systematic review and meta-analysis comparing laboratory results and pain perception between self-collected capillary and venous blood samples. From 1,436 identified studies, 26 met the inclusion criteria. The overall correlation between capillary BSC and venous samples was strong (r = 0.89, 95 % CI: 0.86-0.92) with high heterogeneity (I2 = 94.2 %). For dichotomous outcomes, concordance was excellent (0.99, 95 % CI: 0.98-1.00). Capillary BSC was associated with significantly lower pain scores than venipuncture (SMD = -0.65, 95 % CI = -0.96; -0.35), with upper arm devices having lower pain scores compared to fingerprick methods. Despite methodological heterogeneity, capillary BSC shows strong agreement with venous sampling for most lab parameters and reduces patient discomfort. It appears especially promising for chronic disease monitoring, patients with difficult venous access, and resource-limited settings. Future studies should standardize collection protocols, assess clinical outcomes, and analyze cost-effectiveness. Although no included study showed improved disease management or cost benefits, broader BSC use may enhance healthcare accessibility while maintaining diagnostic accuracy.