Construction and validation of a model to predict nonadherence to guidelines for prescribing antiplatelet therapy to hypertensive patients

Abstract

Objective:

To construct and validate a model to predict nonadherence to guidelines for prescribing antiplatelet therapy (NGAT) to hypertensive patients.

Methods:

This 3 month prospective study was undertaken in 2007–2009 to determine whether 712 hypertensive patients were or were not being prescribed antiplatelet therapy. Outcome: NGAT according to clinical guidelines (just for patients in secondary prevention or with Systematic COronary Risk Evaluation (SCORE) ≥10%). Secondary variables: Duration of hypertension (years), blood pressure (BP), age, gender, smoking, diabetes, dyslipidemia, cardiovascular disease, lipid parameters, SCORE. Of the whole sample 80% was used to construct the model and 20% to validate it. To construct the model, we performed a multivariate logistic regression model which was adapted to be a scoring system with risk groups. The adjusted odds ratios (ORs) were obtained through the model. To validate the model we calculated the area under the ROC curve (AUC) and then compared the expected and the observed NGAT. The final model was adapted for use as a mobile application.

Results:

NGAT: 18.5%, construction; 17.9%, validation. Factors: higher duration of hypertension diagnosis, higher systolic BP, older age, male gender, smoking, diabetes, dyslipidemia and cardiovascular disease. Validation: AUC = 0.82 (95% CI: 0.74–0.90, p < 0.001), with no differences between the observed and the expected NGAT (p = 0.334).

Conclusion:

A tool was constructed and validated to predict NGAT. The associated factors were related with a greater cardiovascular risk. The scoring system has to be validated in other areas.

Keywords: :

• Hypertension
• Models, statistical
• Physicians
• Platelet aggregation inhibitors
• Primary health care

Transparency

Declaration of funding

A research grant from the Department of Clinical Medicine at Miguel Hernández University was used to buy reagents for biochemical testing. This entity had no role in data collection, analysis, or interpretation; nor did it have the right to approve or disapprove publication of the finished manuscript.

Declaration of financial/other relationships

A.P.-B., M.J.M.-O., Z.P.-T., A.S., D.M.F.-d.l.R., D.O.-B., C.C.-M., and V.F.G.-G. have disclosed that they have no significant relationships with or financial interests in any commercial companies related to this study or article.

CMRO peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Acknowledgments

We thank the Conselleria de Sanitat (Comunidad Valenciana) for allowing us to use the health center teams and the health system computerized records. The authors also thank Ian Johnstone for help with the English language version of the text.