Table 2.
Cost-effectiveness analysis of the diagnosis and treatment of early GDM among women with risk factors for hyperglycemia in pregnancy.
| Analysis | Sample size (n) |
Adjusted risk difference in composite adverse pregnancy outcomea ΔE (95% CI) % |
Incremental cost ΔC (95% CI) $ |
ICER ($ per composite adverse pregnancy outcome prevented) | |
|---|---|---|---|---|---|
| Early management group | Usual care group | ||||
| Base case analysis | 400 | 393 | −5.6 (−10.1, −1.2) | −1373 (−3749, 642) | Dominant (cost saving) |
| Sub-group analysis–Glycemic rangeb | |||||
| Higher glycemic rangec | 229 | 231 | −7.8 (−14.6, −0.9) | −2795 (−6638, −533) | Dominant (cost saving) |
| Lower glycemic ranged | 171 | 162 | −2.5 (−10.4, 5.5) | 646 (−1864, 4326) | Not applicablee |
| Sub-group analysis—Timing of oral glucose tolerance test | |||||
| <14 weeks' gestation | 105 | 79 | −8.9 (−15.1, −2.6) | −5548 (−16740, 1547) | Dominant (cost saving) |
| 14–19+6 weeks' gestation | 295 | 314 | −5.0 (−11.6, 1.6) | −409 (−2100, 765) | Dominant (cost saving) |
| Sensitivity analysis (complete case analysis) | 376 | 366 | −5.7 (−9.3, −2.1) | −1465 (−4152, 597) | Dominant (cost saving) |
Note: Statistical significance (p < 0.05) denoted by bold highlight. Abbreviations: $ United States dollar; ΔC Change in cost; ΔE Change in effect; 1HBG 1-h blood glucose; 2HBG 2-h blood glucose; 95% CI: 95% Confidence interval “bias corrected and accelerated”; FBG Fasting blood glucose; GDM Gestational diabetes mellitus; ICER Incremental cost-effectiveness ratio.
Composite adverse pregnancy outcome included pre-term birth <37 weeks' gestation, birthweight ≥4.5 kg, shoulder dystocia, birth trauma, neonatal respiratory distress syndrome, phototherapy requirement for jaundice/hyperbilirubinemia, and/or stillbirth/neonatal death. Adjusted risk difference in composite adverse pregnancy outcome with 95% CI between the intervention and control groups were determined with the use of mixed-effects models, adjusting for six prespecified factors: age, ethnicity, pre-pregnancy body mass index (BMI), primigravidity, education, and current smoking status.25
Glycemic ranges were based upon 1.75 and 2.0-fold risks of adverse pregnancy outcomes at 24–28 weeks' gestation as per the Hyperglycemia and Adverse Pregnancy Outcome (HAPO) study.3,11
Higher glycemic range: FBG 95–109 mg/dl (5.3–6.0 mmol/L), 1HBG ≥191 mg/dl (10.6 mmol/L) and/or 2HBG 162–199 mg/dl (9.0–11.0 mmol/L).
Lower glycemic range: FBG 92–94 mg/dl (5.1–5.2 mmol/L), 1HBG 180–190 mg/dl (10.0–10.5 mmol/L) and/or 2HBG 153–161 mg/dl (8.5–8.9 mmol/L).
ICER was not calculated since the diagnosis and treatment of early GDM was more likely to be harmful for neonates of mothers in the lower glycemic range due to a possibility of an increased risk of small-for-gestational-age infants. Statistical significance denoted by bold highlight.