Clinical, laboratory, and medication-related factors associated with in-hospital mortality among oncology patients at a tertiary hospital in Saudi Arabia.

BACKGROUND

Oncology inpatients face physiological decline alongside complex pharmacology, yet clinical mortality predictors and drug-related risks remain understudied in Middle Eastern populations. This study identified independent predictors of in-hospital mortality and characterized potential drug-drug interactions (pDDIs) among hospitalized cancer patients in Saudi Arabia.

METHODS

This retrospective cohort study evaluated 401 adult oncology inpatients admitted to a tertiary care center in Hail, Saudi Arabia (2020-2022). Demographics, clinical parameters, and medication profiles were extracted from medical records. Bivariate correlations were assessed using point-biserial ( r p b ) and phi ( ϕ ) coefficients. Independent mortality predictors were identified via multivariable binary logistic regression, and biomarker discrimination was evaluated using receiver operating characteristic (ROC) curves. Potential DDIs were screened using Drugs.com.

RESULTS

The cohort was predominantly female (67.6%) and Saudi (85.0%), with solid malignancies accounting for 94.3% of cases. In-hospital mortality was 25.2% ( n = 101 / 401 ). Bivariate correlations demonstrated significant associations with mortality across clinical parameters, including mechanical ventilation requirements ( ϕ = 0.118 , p = 0.018 ). Multivariable regression identified four independent physiological predictors of mortality: renal failure ( aOR = 44.29 , 95 %  CI : 1.07 - 1836.31 ), baseline albumin aOR = 0.71  per  g / L , 95 %  CI : 0.55 - 0.91 , serum creatinine ( aOR = 1.02  per  μ mol / L , 95 %  CI : 1.001 - 1.04 ), and oxygen saturation ( aOR = 0.68  per  % , 95 %  CI : 0.50 - 0.93 ). Serum albumin showed high individual discrimination ( AUC = 0.920 ), while the combined multivariable model achieved an AUC of 0.953. Pharmacological screening revealed near-universal interaction prevalence: 98.6% of 2,148 prescriptions contained a pDDI flag (54.9% severe), and 96.5% of patients had ≥ 1 severe pDDI flag.

CONCLUSION

In-hospital mortality is strongly driven by acute organ dysfunction and physiological decline rather than database-flagged interactions alone. However, the high prevalence of severe pDDI flags highlights a critical need to integrate structured clinical pharmacy reviews into oncology admission protocols. Targeted medication safety interventions should focus on avoiding nephrotoxic combinations and establishing pre-therapeutic pharmacogenetic screening to mitigate potential iatrogenic risks.