Table 2Studies Modeling Screening for Type 2 Diabetes (KQ1)

Author Year (in date order)Type of screening;
Perspective
Type of model;
Time horizon
Population
Country
Included costs;
Discount rate
InterventionOutcomesConclusionsQuality assessment
CDC Diabetes Cost-Effectiveness Study Group 199890One-time opportunistic screening during regular physician visit;
Single-payer health care system
Monte Carlo computer simulation model

Lifetime or age 95y
10,000 cohort with newly-diagnosed DM2; general population

US
Used data from DM1 for microvascular disease risk reduction with treatment

3% annual rate
One-time screening intervention with FPG, OGTT for confirmation of positivesIncremental cost of screening is $236,449 per life-year gained and $56,649/QALY; more CE among younger persons and among African AmericansScreening may produce cost/QALY within range of currently acceptable, especially for younger persons

Model does not take into account effect of blood glucose control on CVD
Limited sensitivity analyses
CVD not modeled; screening and treatment only influence microvascular complications
No information on how QALYs determined
No mention harms of screening
Lack of transparency of details of model
Used data from DM1 for microvascular disease risk reduction with treatment
Goyder et al, 200091Universal screening

Perspective: NA (does not involve cost)
Decision analysis

Lifetime
10,000 cohort

UK
NA

3% annual rate for QALYs
Various interventions for hyperglycemia, HT, lipidsQALYs gained by screening 10,000 persons: 10.5The immediate disutility of earlier diagnosis and additional treatment may be greater than the potential long-term benefit from postponing microvascular complications; screening decisions should be based largely on CVD risk and interventions to reduce that riskUsed data from DM1 for microvascular disease risk reduction with treatment
Details and assumptions of the model not clear
Hofer et al, 200092Mass screening

Not an economic analysis
Markov model

Lifetime
Recent onset of diabetes (<5y) derived from NHANES IIINAHypertension and lipid NHANES III; DCCTNumber blind/1000 diabetics age 40y, A1c 12%:
Case finding: 141
Perfect screening: 133
Case finding, A1c <9%: 90
Screening, A1c <9%: 41
Screening produces 7% of the benefit of reduced number of cases of blindness; improved treatment alone is 65%
Largest impact of improving treatment and diagnosis is in younger persons with high A1c; focus should first be on improving glycemic control of known diabetics with high A1c; if that is achieved, then the benefits of screening will become more importantDoes not include benefits of HT and lipid treatment
Only examines microvascular complications
Chen et al, 200143Mass screening

Single payer health plan
Markov process

Monte Carlo simulation

30y or death
Over age 30y, general community population

Taiwan
Direct costs including costs of screening, treatment

3% annual rate
Screening program lasts for 10y; standard treatments such as that of UKPDS for persons with DM2Cumulative incidence rates of microvascular complications with screening:
2y frequency: Blindness: 3.06%; ESRD: 0.19%; LEA: 0.97%
5y frequency: Blindness 3.13%; ESRD: 0.19%; LEA: 0.99%
Control (no screening): Blindness: 4.3%; ESRD: 0.54%; LEA: 1.43%
NSD between 2 and 5y screening

CE (cost/QALY): 2y: $17,833; 5y: $10,531
Incremental cost/QALY: lowest 40–49y group ($9,193), highest 70+y ($36,467)
Mass screening is relatively cost-effective compared to opportunistic screening as costs incurred with mass screening are offset with life-years gained
Mass screening for DM2 is relatively cost-effective compared to other screening interventions (e.g., cervical cancer or HT)
Screening is more cost-effective in younger than older persons

Model focuses on microvascular complications
Lack of transparency for assumptions, data synthesis
No sensitivity analyses
Does not include CVD risk reduction in model
Does not include adverse effects of screening
Hoerger et al, 200487One-time opportunistic screening targeted to persons with HT

Health care system perspective
Markov

Lifetime
General primary care population

US
Direct medical costs: screening, diagnostic tests, treatment

3% annual rate
Treatment of HT to goal of DBP 80mm Hg (HOT); intensive glycemic control for diagnosed DM2 (UKPDS)Results per true diabetes case, compared to no screening:
QALYs gained per person screened (cost/QALY):
Targeted screening for people with HT only: range 0.08 with screening at 35y ($87,096) to 0.23 for screening at 65y ($31,228)
Universal screening: range 0.05 with screening at 35y ($126,238) to 0.11 for screening at 75y ($48,146)
Universal vs targeted screening, incremental cost/QALY: 35y: $143,830; 75y $443,433
Targeting screening to persons with HT is more CE than universal screening at every age when each alternative is compared to no screening
Targeted and universal screening more CE when take into account reduction in CVD events from earlier treatment of HT for ages 55, 65, 75 than for 35 and 45y
The most CE approach to one-time screening: target people with HT 55 to 75y
Benefit of screening comes mainly from reducing CVD events by control of HT rather than from reducing microvascular complications
Did not include adverse effects of screening
Thorough sensitivity analyses
Includes sub-models for CVD and stroke
Includes benefits for tight BP control, but not other CVD risk reduction interventions
Assumes 100% uptake and follow-up
Glumer et al, 200693Population screening

Health care system
Population-based simulation model

5y
Community-based

Denmark
Screening and treatment for DM2 and complicationsBased on community sample age 30–60yLeast conservative model (low costs and multiplicative risk reduction for combined treatments): Cost/number of events prevented: £23,000 to 82,000; major contributors to uncertainty: risk reduction for hypertension treatment and UKPDS risk model intercept

Model not sensitive to decisions about which groups to screen nor to costs of screening or treatment; model strongly affected by assumptions about how treatments combine to reduce risk.
There is considerable uncertainty about the CE of screening for DM2; the most important parameter is the effect of treatment and whether risk reductions are multiplicative or additiveModel combines effects of treatment of hyperglycemia, hypertension and dyslipidemia
Time horizon only 5y
Waugh et al, 200713Population screening

National Health Service
Markov

Lifetime
General population

UK
Screening and treatment for DM2 and complications
3.5% for costs and benefits
Screen with A1c then OGTT
Various interventions for hyperglycemia, HT, lipids
Cost reduction and QALYs gained from fewer CVD events, largely from statin treatment, as well as fewer microvascular complicationsScreening is relatively cost-effective for persons 40–70y; more CE for the older group and for persons with hypertension or obesityIncludes macro and microvascular complications; relatively simple model

Abbreviations: BP, blood pressure; CVD, cardiovascular disease; DBP, diastolic blood pressure; DCCT, Diabetes Control and Complications Trial; DM1, diabetes mellitus type 1; DM2, diabetes mellitus type 2; CDC, Centers for Disease Control and Prevention; CE, cost-effectiveness; ESRD, end-stage renal disease; FPG, fasting plasma glucose; HOT, Hypertension Outcomes Trial; HT, hypertension; LEA, lower extremity amputations; NA, not applicable; NHANES, National Health and Nutrition Examination Survey; NSD, no significant difference; OGTT, oral glucose tolerance test; QALYs, quality adjusted life-years; UK, United Kingdom; UKPDS, United Kingdom Prospective Diabetes Study; y, year(s).

From: Summary Tables

Cover of Screening for Type 2 Diabetes Mellitus: Update of 2003 Systematic Evidence Review for the U.S. Preventive Services Task Force
Screening for Type 2 Diabetes Mellitus: Update of 2003 Systematic Evidence Review for the U.S. Preventive Services Task Force [Internet].
Evidence Syntheses, No. 61.
Norris SL, Kansagara D, Bougatsos C, et al.

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