Type 2 diabetes (T2D) screening once every 3 years has been found to be more cost-effective than annual screening among the the obese and elderly in all age groups and in overweight individuals between 45 to 59-years of age compared with an annual interval and intervals tailored to risk stratification groups based on age and body mass index (BMI), according to an investigative study published in BMC Endocrine Disorders.
Investigators created a state transition model of screening results and progression of T2D to replicate lifetime diabetes-related healthcare costs per quality-adjusted life year (QALY). The researchers divided the patient population first based upon age into 3 groups: 30-44, 45-59, and 60-74 years of age. Then, they stratified each age category based upon BMI calculations with underweight <18.5, normal between 18.6 and 24.9, overweight between 25 and 29.9, and obese ≥30. The cycle length of the model equaled 1 year. The researchers used a willingness-to-pay threshold of $50,000 per QALY as the predetermined accepted level for the incremental cost-effectiveness ratio.
The researchers calculated the sensitivity and specificity of the test based upon the data set obtained for each population. They used the calculated sensitivity and specificity when recommending different screening intervals based on risk stratification.
The costs per QALY for 3-year glycated hemoglobin (HbA1c) interval screenings totaled $15,034 for obese individuals aged 30 to 44, $11,849 for obese individuals aged 45 to 59, $8685 for obese individuals aged 60 to 74, and $18,918 for overweight individuals aged 45 to 59.
The costs/QALY for 3-year interval screenings for those in the 60- to 74-year-old age group totaled $11,377 for underweight individuals, $18,123 for individuals with normal weight, and $12,537 for overweight individuals. In the younger age and lower BMI stratified groups, the optimal HbA1c screening intervals were longer than 3 years.
Direct costs included the cost of the HbA1c screening test, which was approximately $80, as well as the cost of T2D treatment based on published cost data. The investigators did not include indirect costs in the scope of this study.
Uncertainties in this study included real-world likelihoods of patients who do not visit clinics for treatment even after they receive positive results by screening tests. The authors had to retrieve data from the report comparing new vs traditional treatment regimens. Due to lack of data accessibility, the researchers did not include family and patient medical history including hyperlipidemia, hypertension, and prediabetes in their risk stratification.
“When optimal screening intervals are introduced based on patient risk stratification, it would be possible to eliminate unnecessary tests as well as to minimize the change of failing to detect affected patients,” the researchers said. They suggested that “patient risk stratification, HbA1c test characteristics, and economic impact on public health not only should be used as the basis of health policy but also should be integrated and evaluated to maximize the effectiveness of mass screening.”
Ohde S, Moriwaki K, Takahashi O. Cost-effectiveness analysis for HbA1c test intervals to screen patients with type 2 diabetes based on risk stratification. BMC Endocr Disord. 2021;21(1):105. doi:10.1186/s12902-021-00771-0