Development and validation of the synthetic index of palliative care integration into primary health care

Abstract Background Integrating palliative care (PC) into primary health care (PHC) is essential to achieve universal health coverage and equity. However, most countries lack concise and validated tools to monitor this process. This study developed and validated a composite index to measure the degree of PC integration into PHC at the departmental level in Colombia. Methods An ecological, cross-sectional study was conducted across 33 territorial units in Colombia (32 departments plus Bogotá D.C.) in 2024. Eight of 15 candidate indicators were retained to construct the index. Each indicator was normalized using a Min–Max linear transformation [0–1] and analyzed through principal component analysis with varimax rotation. The Synthetic Index of Palliative Care Integration into Primary Health Care (SIPCI) was built using a hierarchical weighting scheme combining domain-level and within-domain weights. Stability was assessed through jackknife leave-one-out, alternative normalizations methods, and four robustness scenarios including Monte Carlo perturbations. External validity was examined through correlations with socioeconomic and service-related variables. Results SIPCI scores ranged from 0.04 to 0.71 (mean 0.38, SD 0.13). Overall, 52% of departments showed low or medium-low integration, while 48% showed medium-high or high integration. A clear spatial gradient was observed, with higher integration in central departments and Bogotá, and lower integration in Amazon and Orinoquia regions. Sampling adequacy was good (KMO = 0.742). Information loss was low (NMSE = 0.13; 0.10 after indicator reduction). Leave-one-out analyses showed strong concordance with the baseline index (Spearman $$ > 0.94$$ ; Kendall $$ > 0.86$$ ). Five subcomponents were identified, which rural accessibility and undergraduate PC training contributing most. The correlation between SIPCI and departmental income was positive but moderate, indicating that economic capacity may facilitate, but does not determine integration. Conclusions The SIPCI provides a reproducible, system-level measure for monitoring and benchmarking territorial patterns of palliative care integration within primary health care in Colombia. The findings describe marked geographic heterogeneity and support the use of SIPCI for routine monitoring and planning, without implying causal mechanisms or patient-level effects. Although the index showed good internal coherence and robustness, further studies may help strengthen its construct validity and assess its applicability in other settings.