The cost and effectiveness of adherence-improving interventions for antihypertensive and lipid-lowering drugs*.

AIMS: Adherence to cardiovascular medications is poor. Accordingly, interventions have been proposed to improve adherence. However, as intervention-associated costs are rarely considered in full, we sought to review the effectiveness and costs associated with different adherence-improving interventions for cardiovascular disease therapies. METHODS: We reviewed MEDLINE to update a prior review of interventions to improve adherence with antihypertensive and/or lipid-lowering therapy covering January 1972 to June 2002, to add studies published from July 2002 to October 2007. Eligible studies evaluated > or = 1 intervention compared with a control, used measures other than self-report, reported significant improvement in adherence and followed patients for > or = 6 months. Effectiveness was measured as relative improvement (RI), the ratio of adherence in the intervention group to the control group. Costs were calculated based on those reported in the analysis, if available or estimated based on resource use described. All costs were truncated to 6 months and adjusted to 2007 US$. RESULTS: Of 755 new articles, five met all eligibility criteria. Combining with the prior review gave 23 interventions from 18 studies. RI in adherence ranged from 1.11 to 4.65. Six-month intervention costs ranged from $10 to $142 per patient. Reminders had the lowest effectiveness (RI: 1.11-1.14), but were least costly ($10/6 months). Case management was most effective (RI: 1.23-4.65), but the most costly ($90-$130/6 months). CONCLUSIONS: Generally, we found a positive association between intervention costs and effectiveness. Therefore, consideration of intervention costs, along with the benefits afforded to adherence, may help guide the design and implementation of adherence-improving programs.

Drug titration patterns and HbA 1c levels in type 2 diabetes.

OBJECTIVE: To evaluate oral antidiabetes drug (OAD) use, haemoglobin A(1c) (HbA(1c)) testing and glycaemic control in type 2 diabetes patients. STUDY DESIGN: Retrospective analysis based on claims data from the Integrated Healthcare Information Services (IHCIS) National Managed Care Benchmark Database. METHODS: OAD use and HbA(1c) testing were analysed for patients with >or= 2 claims indicating diagnosis of type 2 diabetes and >or= 1 90-day OAD treatment period between 1 January, 2000 and 30 June, 2006. Likelihood of HbA(1c) testing was examined using multivariable logistic regression analyses, adjusting for OAD regimen and patients' sociodemographical characteristics. RESULTS: Patients were classified based on initial OAD regimen: metformin (MET) (n = 22,203; 41.3%), sulphonylurea (SFU) (n = 18,439; 34.3%), thiazolidinedione (TZD) (n = 7663; 14.3%), SFU + MET (n = 5467; 10.2%) and TZD + MET (n = 2355; 4.2%). A total of 51.5% of patients had HbA(1c) testing during 90 days preceding OAD initiation through regimen completion. Approximately, 65% of MET and 58% of SFU patients had no titration of initial regimen. Patients demonstrating inadequate glucose control decreased from 68.5% at baseline to 46.9% within 90 days of regimen initiation. Multivariable logistic regression indicated several negative predictors of HbA(1c) testing, including SFU use, age 65+ years, moderate insurance copayment and preindex inpatient utilisation. Multivariable logistic regression of variables associated with reduced likelihood of up-titration included TZD, SFU + MET, or TZD + MET treatment, age 18-34 years, Medicare insurance and any preindex healthcare utilisation. CONCLUSIONS: Patients are not being transitioned to additional OADs in a stepwise fashion and/or are receiving inadequate titration on current OAD regimens. The low rate of HbA(1c) testing and rates of control are contributing factors.