Understanding the inter-relationship between improved glycaemic control, hypoglycaemia and weight change within a long-term economic model.
BACKGROUND
Current guidelines for the management of type 2 diabetes advocate the attainment of sustained near normal glycaemia levels. Metformin is widely accepted as the treatment of choice for the initiation of pharmacotherapy; however, secondary failure of oral monotherapy occurs in 60% of patients resulting in the need for multiple pharmacotherapies. Therapy-related consequences of treatment, such as weight gain and hypoglycaemia impact on the cost-effectiveness profile of various agents. We therefore sought to ascertain the respective contribution of hypoglycaemia, weight change and improved blood glucose control on second-line therapy options added to metformin.


METHODS
This study uses a simulation model designed to evaluate the cost utility of new therapies in a population of patients with type 2 diabetes mellitus. Standard model outputs include incidence of micro- and macrovascular complications and diabetes-specific and all-cause mortality.


RESULTS
The mean discounted quality-adjusted life year (QALY) predicted by the model was 12.31 years. Reducing Glycosylated haemoglobin (HbA1c) by 1% gave a predicted gain of 0.413 QALYs per patient. A 3-kg weight loss and 30% reduction in hypoglycaemia frequency produced a combined QALY gain of 0.355, whereas the reverse gave a QALY decrement of 0.356.


CONCLUSIONS
The results of this analysis quantify the QALY decrement that may result from adverse therapy effects. The beneficial effects of improved glycaemic control on QALYs may be offset by characteristic treatment-specific adverse effects, such as weight gain and hypoglycaemia frequency.
McEwan
P
P
Cardiff Research Consortium, Cardiff, Wales, UK. phil.mcewan@capita.co.uk
Evans
M
M
Kan
H
H
Bergenheim
K
K
D001786:Blood Glucose / Q000187:drug effects*; D001835:Body Weight / Q000187:drug effects*; D003362:Cost-Benefit Analysis; D003924:Diabetes Mellitus, Type 2 / Q000188:drug therapy* / Q000191:economics; D006801:Humans; D007003:Hypoglycemia / Q000191:economics / Q000517:prevention & control*; D007004:Hypoglycemic Agents / Q000191:economics / Q000627:therapeutic use*; D008297:Male; D008687:Metformin / Q000191:economics / Q000627:therapeutic use*; D008875:Middle Aged; D018803:Models, Economic
D001786:Blood Glucose; D007004:Hypoglycemic Agents; D008687:Metformin