Intensive therapy extended life and was cost-effective for IDDM
ACP J Club. 1997 Mar-Apr;126:53. doi:10.7326/ACPJC-1997-126-2-053
The Diabetes Control and Complications Trial Research Group. Lifetime benefits and costs of intensive therapy as practiced in the Diabetes Control and Complications Trial. JAMA. 1996 Nov 6;276:1409-15.
To determine the lifetime benefits and costs of intensive therapy for the 17% of patients in the United States with insulin-dependent diabetes mellitus (IDDM) who would have been eligible for enrollment in the Diabetes Control and Complications Trial (DCCT).
Cost-effectiveness analysis using a Monte Carlo simulation model and a health care system payer perspective.
29 academic medical centers in North America.
A hypothetical sample of 120 000 patients who met eligibility criteria for the DCCT. DCCT criteria included age 13 to 39 years and either IDDM for 1 to 5 years and no retinopathy or microalbuminuria or IDDM for 1 to 15 years, minimal to moderate non-proliferative retinopathy, and urinary albumin excretion rate of < 200 mg/24 hours.
The disease characteristics of each patient were categorized using 12 health states according to the extent of retinopathy, nephropathy, and neuropathy; the model simulated the course of disease for each patient's lifetime. The probability of advancement to a more severe stage of disease depended on current health state, therapy (intensive vs conventional), and treatment duration. At the end of the simulation, time spent in each treatment and health state and time alive were calculated and costs were assigned by treatment group.
Main cost and outcome measures
Costs of therapy were based on resources actually used in the DCCT. Complication management costs were based on consensus and Medicare benefits. Outcomes included life-years gained; additional years free of blindness, end-stage renal disease, amputation, and complications; lifetime costs per patient (U.S. dollars); and quality-adjusted life years (QALYs).
Compared with conventional therapy, intensive therapy resulted in a mean gain of 5.1 life-years/patient. Extrapolated to the patients meeting DCCT entry criteria, intensive therapy would result in 611 000 additional years of life. Patients who received intensive therapy would gain a mean of 7.7 additional years of sight, 5.8 additional years free from end-stage renal disease, 5.6 additional years free from lower-extremity amputation, and 15.3 additional years free from onset of substantial microvascular or neurologic complications. The expected lifetime cost per patient was $99 822 for intensive therapy and $66 076 for conventional therapy. Extrapolated to the 120 000 patients, intensive therapy would cost about $4 billion more than conventional therapy. The incremental cost per year of life gained and per QALY gained were $28 661 and $19 987, respectively.
In patients with IDDM, the lifetime benefits and costs of intensive therapy were greater than those of conventional therapy. Intensive therapy was considered to be cost-effective.
Source of funding: National Institutes of Health.
For article reprint: DCCT Research Group, Box NDIC/DCCT, Bethesda, MD 20892, USA.
Readers of this study by the DCCT Research Group should ask 3 questions. First, are the projected gains in health status from intensive glucose control for patients with IDDM large or small? The simple answer is: The gains are large. Some clinicians may have difficulty interpreting the meaning of improvements measured in additional life years, and they are referred to an article by Naimark and colleagues (1). Relative to other widely adopted therapies, such as β-blockers after myocardial infarction and angiotensin-converting enzyme inhibitors for heart failure that are modeled to result in 2 months to 1.2 additional life years (2), the projection of 5.1 additional life years in this study is large.
Second, are the incremental costs required to achieve the health gains high or low? The answer is: The costs are moderately low. Compared with other health care interventions, the $28 661 per year of life gained and $19 987 per incremental QALY gained are attractive (3, 4).
Third, are the projections based mostly on modeling and speculation or are they based on primary data? The key part of the sophisticated modeling technique used here is disease progression over time. These estimates were indeed based on primary data from a high-quality randomized trial. To this reviewer, the analysis is about as good as it gets.
The DCCT has provided patients, clinicians, and policy makers with valuable information about the clinical effects and economic attractiveness of intensive glucose control for patients with IDDM. It should set the standard for others who wish to promote widespread adoption of any health care technology.
Allan S. Detsky, MD, PhD
University of TorontoToronto, Ontario, Canada