A cost-effectiveness analysis of pioglitazone plus metformin compared with rosiglitazone plus metformin from a third-party payer perspective in the US.
OBJECTIVE
The long-term cost-effectiveness of using pioglitazone plus metformin (Actoplusmet dagger) compared with rosiglitazone plus metformin (Avandamet double dagger) in treating type 2 diabetes (T2DM) was assessed from a US third-party payer perspective.


METHODS
Clinical efficacy (change in HbA(1c) and lipids) and baseline cohort parameters were extracted from a 12-month, randomized clinical trial (Derosa et al., 2006) evaluating the efficacy and tolerability of pioglitazone versus rosiglitazone, both in addition to metformin, in adult T2DM patients with insufficient glucose control (n = 96). A Markov-based model was used to project clinical and economic outcomes over 35 years, discounted at 3% per annum. Costs for complications were taken from published sources. Base-case assumptions were assessed through several sensitivity analyses.


METHODS
Outcomes included incremental life-years, quality-adjusted life-years (QALYs), total direct medical costs, cumulative incidence of complications and associated costs, and incremental cost-effectiveness ratios (ICERs).


RESULTS
Compared to rosiglitazone plus metformin, pioglitazone plus metformin was projected to result in a modest improvement in 0.187 quality-adjusted life-years. Over patients' lifetimes, total direct medical costs were projected to be marginally lower with pioglitazone plus metformin (difference -$526.), largely due to reduced CVD complication costs. While costs were higher among renal, ulcer/amputation/neuropathy, and eye complications in the pioglitazone plus metformin group, the cost savings for CVD complications outweighed their economic impact. Pioglitazone plus metformin was found to be a dominant long-term treatment strategy in the US compared to rosiglitazone plus metformin. Sensitivity analyses showed findings to be robust under almost all scenarios, including short-term time horizons, 6% discounting, removal of individual lipid parameters, and modifications of patient cohort to more closely represent a US T2DM population. Pioglitazone plus metformin was no longer dominant with 0% discounting, with 25% reduction in its HbA(1c) effects, or with a 15% increase in its acquisition price.


CONCLUSIONS
Under a range of assumptions and study limitations around cohorts, clinical effects, and treatment patterns, this long-term analysis showed that pioglitazone plus metformin, when compared to rosiglitazone plus metformin, was a dominant treatment strategy within the US payer setting. Results were driven by the combination of modest differences in QALYs and modest savings in total complication costs over 35 years.
St Charles
Meaghan
M
IMS Health, Falls Church, VA, USA.
Minshall
Michael E
ME
Pandya
Bhavik J
BJ
Baran
Robert W
RW
Tunis
Sandra L
SL
D000368:Aged; D015897:Comorbidity; D003362:Cost-Benefit Analysis; D048909:Diabetes Complications / Q000191:economics / Q000453:epidemiology / Q000628:therapy; D003924:Diabetes Mellitus, Type 2 / Q000150:complications / Q000188:drug therapy* / Q000191:economics* / Q000453:epidemiology; D004338:Drug Combinations; D005260:Female; D006801:Humans; D007004:Hypoglycemic Agents / Q000008:administration & dosage / Q000191:economics; D007349:Insurance, Health, Reimbursement / Q000191:economics; D008297:Male; D008687:Metformin / Q000008:administration & dosage / Q000191:economics; D008875:Middle Aged; D000077205:Pioglitazone; D000077154:Rosiglitazone; D045162:Thiazolidinediones / Q000008:administration & dosage / Q000191:economics; D014481:United States / Q000453:epidemiology
D004338:Drug Combinations; D007004:Hypoglycemic Agents; D045162:Thiazolidinediones; D000077154:Rosiglitazone; D008687:Metformin; D000077205:Pioglitazone