OBJECTIVES: To study the departmental and regional inequality of the infant mortality rate (IMR) in Colombia in 1993 and 2019.

METHODS: an ecological study that measures the regional inequalities of the IMR in Colombia was carried out for the years 1993 and 2019. For this, indicators as incidence rate (IR) and difference of rates (DR), effects index and Population-attributable risk (PAR), were used. To measure poverty, Unmet Basic Needs (UBN) was used. Data was obtained from the national agency for population statistics – known as DANE for its initials in Spanish.

RESULTS: In 1993 and 2019 the IMR in Colombia was 33.7 and 17.3 respectively. In 1993 the absolute difference between the departments with major and minor poverty (Chocó: 80.4%; Bogotá, D.C.:17.3%) was 63.1%. For 2019, this difference became 55.9%. For the same years, between these departments the IR of infant mortality was 2.9 and 3.9 and the DR was 56.4 and 56.2, respectively. The poverty (UBN) explained, to a large extent, the infant mortality in 2019 in comparison with 1993 (R² 2019: 89.4% versus R² 1993: 34.2%). The β coefficient of the lineal regression for 1993 was 0.3393 (CI95%:0.1669-0.5518) and by each percent point that the UBN decreased in the departments, a reduction in the IMR of 0.3393 deaths by each one thousand born alive was observed. For 2019, this reduction was 0.7909 by each one thousand born alive (CI95%: 0.6931-0.8888)

CONCLUSIONS: Although in Colombia infant mortality has been reduced by half in aggregate terms, the great inequalities between departments and regions, associated with poverty, have been maintained and their relationship with the IMR has increased.