Adverse Drug Reactions in an Ageing PopulaTion risk Prediction (ADAPTiP) tool: development of a prediction model related to hospital admissions

Background
Older patients are at an increased risk of developing adverse drug reactions (ADRs). The aim of this study was to develop a risk prediction model (ADAPTiP) for ADR-related hospital admissions in older populations, based on predictors available at the time of hospital admission.

Methods
Using the Adverse Drg reactions in an Ageing PopulaTion (ADAPT) cohort (N=798; 361 ADR-related admissions; 437 non-ADR-related admissions), a cross-sectional and prospective cohort study designed to examine the prevalence of and risk factors for ADR-related hospital admissions in patients aged ≥ 65 years, twenty predictors (categorised as sociodemographic-related, functional ability-related, disease-related and medication-related) were considered in the development of the model. A multivariable logistic regression model was developed using statistically significant univariate associations and/or clinically relevant predictors to estimate adjusted odds ratios and 95% confidence intervals (CI). Calibration and discriminative performance of the model was assessed by the Hosmer-Lemeshow test and by calculating the area under the receiver operator characteristic (AUROC) curve.

Results
The multivariable model (ADAPTiP) included ten predictors; age, frailty, chronic lung disease, antithrombotic agents, diuretics, renin angiotensin aldosterone system (RAAS) drug classes, primary presenting complaints of respiratory, bleeding, gastrointestinal disorders and syncope on hospital admission. Antithrombotic agents, diuretics and RAAS drug classes and the primary presenting complaints of bleeding disorders, gastrointestinal disorders and syncope and frailty were significantly associated with an ADR-related hospital admission. Whereas, increasing age and presence of chronic lung disease were significantly associated with having a non-ADR-related hospital admission. The AUROC was 0.78 [95%CI:0.75;0.81] with sensitivity and specificity values of 59% and 83%, respectively.

Conclusion
ADAPTiP has the potential for use as a risk prediction model for ADR-related hospital admissions. Future research will validate this model in other settings.