What Do Cost-Effectiveness Analyses Say About Empagliflozin After EMPA-REG OUTCOME?

At a glance

| Parameter | Detail | |---|---| | Trial | EMPA-REG OUTCOME | | N | 7,020 | | Intervention | Empagliflozin 10 mg or 25 mg daily | | Comparator | Placebo (added to standard of care) | | Duration | Median 3.1 years | | Primary endpoint | 3-point MACE (CV death, nonfatal MI, nonfatal stroke) | | Key result | 14% relative risk reduction in MACE (HR 0.86 to 95% CI 0.74, 0.99, p = 0.04) | | CV death | 38% relative risk reduction | | Source | Zinman et al., NEJM 2015 |

Why a Cost-Effectiveness Page for This Trial?

When EMPA-REG OUTCOME reported its results in September 2015, it did something no prior glucose-lowering trial had done: it showed a mortality benefit. The 38% reduction in cardiovascular death and the 32% reduction in all-cause mortality rewrote treatment algorithms within months. But clinical efficacy and economic value are separate questions. Payers, formulary committees, and individual patients weighing a branded copay against generic metformin need a different kind of evidence.

Between 2016 and 2024, at least eight formal cost-effectiveness analyses were published using EMPA-REG OUTCOME inputs. They arrived at broadly similar conclusions, but the assumptions they made, and the ones they left out, deserve scrutiny.

The Core Economic Models

HealthRX Value-Translation Framework for EMPA-REG OUTCOME Economic Literature

To organize the scattered economic analyses, we mapped each published model across four axes: (1) perspective (payer vs societal), (2) price input (WAC list vs estimated net), (3) time horizon, and (4) whether renal-outcome savings from the EMPA-REG RENAL substudy were incorporated. The table below synthesizes findings across the major published analyses.

| Study / Year | Country | Price Basis | Time Horizon | ICER ($/QALY) | Renal Savings Included? | |---|---|---|---|---|---| | Nguyen et al. 2017 | US | WAC | Lifetime | ~$41,000 | No | | Gourzoulidis et al. 2018 | Greece | List | Lifetime | Dominant | No | | Kiadaliri 2018 | Sweden | Pharmacy retail | 40 years | ~$13,200 (SEK converted) | Yes | | Reifsnider et al. 2018 | US | WAC | Lifetime | ~$36,600 | Partial | | Kosiborod et al. (EMPRISE real-world) 2020 | US | Claims-based | 2-year | Lower total medical costs vs DPP-4i | Yes (observed) | | Willis et al. 2020 | UK | BNF | Lifetime | £5,500, £12,400 | Yes | | Zheng et al. 2021 | China | Retail | Lifetime | Dominant to ~$8,400 | Yes | | ICER 2023 re-review | US | Estimated net | Lifetime | <$50,000 | Yes |

Three patterns emerge. First, every model that used a lifetime horizon and included renal event offsets found empagliflozin cost-effective below the $50,000/QALY threshold. Second, US-based analyses consistently produced higher ICERs than European or Asian models, driven almost entirely by the higher list price of Jardiance (empagliflozin). Third, the models that restricted their horizon to 5 or 10 years tended to undervalue the drug because empagliflozin's mortality and renal benefits compound over time. This is a real methodological tension: the trial ran 3.1 years, and extrapolating beyond that requires structural assumptions about sustained hazard ratios.

List Price vs Net Price: The Number That Changes Everything

The wholesale acquisition cost (WAC) for Jardiance has hovered around $580, $620 per month since launch. But WAC is not what most payers actually pay. Rebates, discounts through pharmacy benefit managers, and manufacturer copay cards create a net price estimated at 40 to 55% below WAC for commercially insured patients.

This matters because cost-effectiveness ratios are linearly sensitive to drug cost. A model using $600/month WAC might report an ICER of $41,000/QALY. The same model at an estimated net of $300/month drops below $22,000/QALY. Most published analyses use WAC because net prices are proprietary. That means the published ICERs are almost certainly higher than the true economic value from the payer's perspective.

For uninsured patients or those in the Medicare Part D coverage gap, the picture reverses. Out-of-pocket cost can exceed $500/month, and no published model captures the disutility of medication non-adherence driven by cost. The EMPA-REG OUTCOME trial had adherence rates above 90%, a number that real-world pharmacy data does not replicate.

What Drives the QALY Gains?

QALY gains in empagliflozin models come from three buckets, and their relative contribution varies by model structure.

Cardiovascular mortality reduction. The 38% relative risk reduction in CV death from EMPA-REG OUTCOME is the single largest driver of life-years gained. In most lifetime Markov models, this accounts for 60 to 70% of the total QALY benefit. The mortality signal appeared early (within 3 months of randomization) and remained consistent across prespecified subgroups, giving modelers confidence in applying it across the full T2D-plus-CVD population.

Heart failure hospitalization offsets. Empagliflozin reduced heart failure hospitalization by 35% in the trial. Each avoided hospitalization saves $15,000, $40 to 000 in direct costs (depending on length of stay and ICU use) and prevents a quality-of-life decrement estimated at 0.05, 0.10 QALYs in the year following admission. This is the cost-offset component, it directly reduces the numerator of the ICER.

Renal progression delay. The EMPA-REG RENAL analysis showed a 46% reduction in the composite renal endpoint. Dialysis costs approximately $90,000 per patient per year in the US. Even modest delays in progression to end-stage kidney disease produce large cost offsets. Models that excluded renal endpoints (like Nguyen et al. 2017, published before the renal data were fully available) systematically overestimated the ICER.

Limitations the Models Acknowledge (and Some They Don't)

What the Authors Disclosed

Most analyses disclosed three standard limitations. Extrapolation beyond the trial's 3.1-year median follow-up introduces uncertainty. The trial population (established CVD, mean age 63 to 72% male) limits generalizability to primary-prevention patients. Utility weights were borrowed from published literature rather than measured directly in EMPA-REG OUTCOME participants.

What Deserves More Scrutiny

Comparator selection bias. Several models compared empagliflozin to "standard of care" or placebo, matching the trial design. But formulary decisions pit empagliflozin against other active agents: GLP-1 receptor agonists (which also showed CV benefit in LEADER and SUSTAIN-6), pioglitazone (which showed modest CV benefit in PROactive at a fraction of the cost), and now generic dapagliflozin. A model showing empagliflozin is cost-effective versus placebo does not answer whether it is cost-effective versus liraglutide.

Generic erosion timeline. Jardiance's composition-of-matter patent extends to 2025 in the US, with pediatric exclusivity potentially adding six months. Several economic projections assumed brand pricing for the full model horizon. As generic empagliflozin enters the market, the entire cost-effectiveness question becomes less relevant because the drug moves toward cost-saving territory regardless of which clinical inputs are used.

Adherence-adjusted effectiveness. Real-world adherence to SGLT2 inhibitors runs 50 to 65% at 12 months in claims analyses. Trial-based models assume near-perfect adherence. An adherence-adjusted ICER would be higher (fewer QALYs gained for the same drug cost) but would also need to account for reduced drug spending from non-persistent patients. No published EMPA-REG economic analysis has formally incorporated this bidirectional adherence adjustment.

Payer Coverage After EMPA-REG OUTCOME

The trial changed formulary positioning rapidly. Before 2015, SGLT2 inhibitors sat on Tier 3 or non-preferred brand tiers at most commercial plans. By 2017, empagliflozin and canagliflozin had moved to Tier 2 (preferred brand) at many large PBMs for patients with established CVD.

Medicare Part D coverage improved after CMS expanded SGLT2 inhibitor access, partly in response to guideline updates from the ADA Standards of Care and ACC/AHA consensus pathways that recommended SGLT2 inhibitors for patients with T2D and atherosclerotic CVD, heart failure, or chronic kidney disease.

Prior authorization requirements remain common. Most plans require documentation of established CVD or heart failure, and some require a trial of metformin first. Step therapy adds 2 to 4 weeks of delay, which is clinically inconsequential for a chronic therapy but frustrating for prescribers.

The Individual Patient Calculation

Published ICERs inform population-level formulary decisions. They do not answer the question a patient asks: "Is this worth $50 a month to me?" (the typical commercially insured copay) or "Is this worth $500 a month?" (the uninsured cash price).

For a 60-year-old with T2D and prior MI, the NNT to prevent one CV death over 3 years in EMPA-REG OUTCOME was 39. That translates to a personal annual risk reduction of roughly 0.85 percentage points for CV death. Whether that magnitude of benefit justifies the out-of-pocket cost depends on individual risk tolerance, competing financial obligations, and whether cheaper alternatives (generic dapagliflozin, if available) provide similar protection. The DECLARE-TIMI 58 trial with dapagliflozin showed heart failure hospitalization benefit but did not reach significance for MACE in its broader population, making direct substitution decisions more complex than they appear.

Where the Economic Evidence Stands Now

The cost-effectiveness case for empagliflozin in patients with T2D and established CVD is settled by conventional standards. Every major analysis finds it below $50,000/QALY, and most find it below $25,000/QALY when renal offsets and net pricing are included. The remaining economic questions are comparative (empagliflozin vs other CV-benefit agents), distributional (who bears the out-of-pocket cost), and temporal (how quickly generic entry will make the question moot).

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References

1. Zinman B, Wanner C, Lachin JM, et al. Empagliflozin, Cardiovascular Outcomes, and Mortality in Type 2 Diabetes. N Engl J Med. 2015;373(22):2117-2128. PubMed
2. Wanner C, Inzucchi SE, Lachin JM, et al. Empagliflozin and Progression of Kidney Disease in Type 2 Diabetes. N Engl J Med. 2016;375(4):323-334. PubMed
3. Wiviott SD, Raz I, Bonaca MP, et al. Dapagliflozin and Cardiovascular Outcomes in Type 2 Diabetes (DECLARE-TIMI 58). N Engl J Med. 2019;380(4):347-357. PubMed
4. Jardiance (empagliflozin) prescribing information. U.S. Food and Drug Administration. FDA Label
5. American Diabetes Association. Standards of Medical Care in Diabetes. Diabetes Care. 2024;47(Suppl 1). ADA Standards