Comparative analyses of published cost effectiveness models highlight critical considerations which are useful to inform development of new models.

Background: Comparative analyses of published cost effectiveness models provide useful insights into critical issues to inform the development of new cost effectiveness models in the same disease area.Objective: The purpose of this study was to describe a comparative analysis of cost-effectiveness models and highlight the importance of such work in informing development of new models. This research uses genotypic antiretroviral resistance testing after first line treatment failure for Human Immunodeficiency Virus (HIV) as an example.Method: A literature search was performed, and published cost effectiveness models were selected according to predetermined eligibility criteria. A comprehensive comparative analysis was undertaken for all aspects of the models.Results: Five published models were compared, and several critical issues were identified for consideration when developing a new model. These include the comparator, time horizon and scope of the model. In addition, the composite effect of drug resistance prevalence, antiretroviral therapy efficacy, test performance and the proportion of patients switching to second-line ART potentially have a measurable effect on model results. When considering CD4 count and viral load, dichotomizing patients according to higher cost and lower quality of life (AIDS) versus lower cost and higher quality of life (non-AIDS) status will potentially capture differences between resistance testing and other strategies, which could be confirmed by cross-validation/convergent validation. A quality adjusted life year is an essential outcome which should be explicitly explored in probabilistic sensitivity analysis, where possible.Conclusions: Using an example of GART for HIV, this study demonstrates comparative analysis of previously published cost effectiveness models yields critical information which can be used to inform the structure and specifications of new models.

Evaluation and management of patients referred to a tertiary-level hypertension clinic in Cape Town, South Africa.

BACKGROUND: Hypertension remains a global health burden, with a high incidence of long-term morbidity and mortality. OBJECTIVE: To evaluate blood pressure (BP) control, factors associated with poor BP control, target organ damage (TOD), white-coat hypertension, treatment-resistant hypertension and secondary hypertension in patients referred to a tertiary-level hypertension clinic. METHOD: This was a prospective case-control study of patients referred for specialist hypertension management. Patient parameters recorded included age, gender, body mass index, uric acid, cholesterol, screening BP, follow-up BP, TOD and medications. We also recorded causes of secondary hypertension. Net BP change and the percentage achieving target BP were calculated in all patients followed up. RESULTS: A total of 175 patients were sampled (72 males and 103 females, mean age 46.5 years). Of the patients 16.6% had a normal screening BP; 62.9% of patients were followed up, and 43.6% of these achieved BP control. After intervention, there was a net drop of 13.2 mmHg (range 7.9 - 18.4) in systolic BP and of 3.8 mmHg (4.4 - 12.0) in diastolic BP. Of all the patients, 12.6% had resistant hypertension, 49.1% had evidence of left ventricular hypertrophy and 18.3% had microalbuminuria; 13.1% of the patients were diagnosed with secondary hypertension. CONCLUSION: Specialist intervention was useful in identifying patients with white-coat and secondary hypertension, as well as in improving hypertension control in patients with apparent treatment-resistant hypertension. However, a significant percentage of patients did not reach target BP, and further efforts are required to identify the underlying causes for this.

Evaluation and Management of Patients Referred to a Tertiary-Level Hypertension Clinic in Cape Town; South Africa

Background. Hypertension remains a global health burden; with a high incidence of long-term morbidity and mortality.Objective. To evaluate blood pressure (BP) control; factors associated with poor BP control; target organ damage (TOD); white-coat hypertension; treatment-resistant hypertension and secondary hypertension in patients referred to a tertiary-level hypertension clinic.Method. This was a prospective case-control study of patients referred for specialist hypertension management. Patient parameters recorded included age; gender; body mass index; uric acid; cholesterol; screening BP; follow-up BP; TOD and medications. We also recorded causes of secondary hypertension. Net BP change and the percentage achieving target BP were calculated in all patients followed up.Results. A total of 175 patients were sampled (72 males and 103 females; mean age 46.5 years). Of the patients 16.6% had a normal screening BP; 62.9% of patients were followed up; and 43.6% of these achieved BP control. After intervention; there was a net drop of 13.2 mmHg (range 7.9 - 18.4) in systolic BP and of 3.8 mmHg (4.4 - 12.0) in diastolic BP. Of all the patients; 12.6% had resistant hypertension; 49.1% had evidence of left ventricular hypertrophy and 18.3% had microalbuminuria; 13.1% of the patients were diagnosed with secondary hypertension. Conclusion. Specialist intervention was useful in identifying patients with white-coat and secondary hypertension; as well as in improving hypertension control in patients with apparent treatment-resistant hypertension. However; a significant percentage of patients did not reach target BP; and further efforts are required to identify the underlying causes for this