Background: In many countries, economic assessments of the routine use of pulse oximetry in the detection of Critical Congenital Heart Disease (CCHD) at birth has not yet been carried out. CCHDs necessarily require medical intervention within the first months of life. This assessment is a priority in low and medium resource countries. The purpose of this study was to assess the cost-effectiveness (CE) relation of pulse oximetry in the detection of cases of CCHD in Colombia. Methods: A full economic assessment of the cost-effectiveness type was conducted from the perspective of society. A decision tree was constructed to establish a comparison between newborn physical examination plus pulse oximetry, versus physical examination alone, in the diagnosis of CCHDs. The sensitivity and specificity of pulse oximetry were estimated from a systematic review of the literature; to assess resource use, micro-costing analyses and surveys were conducted. The time horizon of the economic evaluation was the first week after birth and until the first year of life. The incremental cost-effectiveness ratio (ICER) was determined and, to control for uncertainty, deterministic and probabilistic sensitivity analysis were made, including the adoption of different scenarios of budgetary impact. All costs are expressed in US dollars from 2017, using the average exchange rate for 2017 [$2,951.15 COP for 1 dollar]. Results: The costs of pulse oximetry screening plus physical examination were $102; $7 higher than physical examination alone. The effectiveness of pulse oximetry plus the physical examination was 0.93; that is, 0.07 more than the physical examination on its own. The ICER was $100 for pulse oximetry screening; that is, if one wishes to increase 1% the probability of a correct CCHD diagnosis, this amount would have to be invested. A willingness to pay of $26.292 USD (direct medical cost) per probability of a correct CCHD diagnosis was assumed. Conclusions: At current rates and from the perspective of society, newborn pulse oximetry screening at 24 h in addition to physical examination, and considering a time horizon of 1 week, is a cost-effective strategy in the early diagnosis of CCHDs in Colombia. Trial registration "retrospectively registered".
