Association between serum calcium concentration in patients with osteoarthritis and all-cause mortality and cardiovascular mortality: a retrospective cohort study

Our primary analysis supports an inverse linear association between serum calcium and mortality in OA patients. Although exploratory analyses revealed potential non-linear patterns visually, these were not statistically confirmed. Therefore, the overall relationship is best characterized as linear within the observed range, with lower serum calcium associated with higher mortality risk. Therefore, these findings highlight a potential optimal range for serum calcium but require verification in future studies designed to confirm nonlinearity and assess the clinical utility of calcium management.