Budget Impact Analysis

A budget impact analysis (BIA) is a type of health economic evaluation that estimates the financial consequences of adopting a new health intervention within a specific healthcare setting over a defined time horizon, typically three to five years. Unlike cost effectiveness analysis, which assesses value for money, budget impact analysis focuses on affordability and financial planning.

Even a cost effective intervention may be unaffordable if its adoption requires a large upfront investment or if the eligible patient population is very large. Budget impact analysis answers the practical question: "How much will this cost our healthcare system?" Many health technology assessment bodies and payers, including PBAC in Australia and Canada's Drug Agency (formerly CADTH), require budget impact estimates alongside cost effectiveness analyses, and NICE in England assesses the resource impact of its recommendations. Hospital administrators, insurance payers, and government health ministries use BIA results to plan budgets, negotiate prices, and decide on the pace and scope of adoption. For pharmaceutical and device manufacturers, a well constructed BIA can support reimbursement negotiations by demonstrating that their product is financially manageable.

A budget impact analysis compares two scenarios: the current treatment landscape (without the new intervention) and the future treatment landscape (with the new intervention introduced). The analysis estimates the total cost to the healthcare system under each scenario and calculates the difference.

The first step is to define the eligible patient population: how many patients have the condition, how many meet the criteria for the new intervention, and how many are expected to receive it given real world uptake patterns. Market share estimates are applied to project how the new intervention will displace existing treatments over the time horizon.

The second step is to estimate the per patient costs under each scenario, including drug or device costs, administration costs, monitoring costs, and costs of managing adverse events. The analysis should capture both the costs of the new intervention and any cost offsets (such as reduced hospitalizations or fewer downstream treatments) that result from its use.

The third step is to calculate the total budget impact by multiplying the per patient costs by the number of patients in each scenario and summing across the time horizon. Results are typically presented as the incremental budget impact per year and over the full time horizon.

Budget impact analyses take the perspective of the specific payer or healthcare system making the adoption decision, and they typically do not discount future costs (unlike cost effectiveness analyses), because the focus is on actual cash flows rather than economic efficiency.

Budget impact analysis should be conducted whenever a new health intervention is being considered for adoption, reimbursement, or formulary inclusion. Many health technology assessment bodies, including PBAC in Australia and Canada's Drug Agency, require one in reimbursement submissions. BIA is most useful when the new intervention has a different cost structure from existing treatments, when the eligible population is large, when uptake is expected to be rapid, or when the intervention requires new infrastructure or monitoring programs. It complements rather than replaces cost effectiveness analysis, and both are typically needed to support an adoption or reimbursement decision.

A common error is using unrealistic market uptake assumptions: projecting uptake that is too slow understates the budget impact, while projecting uptake that is too fast overstates it. Uptake projections should be based on evidence from comparable product launches, clinical guidelines, and payer policies. Another mistake is failing to include cost offsets, which can overstate the budget impact by ignoring savings from reduced hospitalizations, fewer emergency visits, or avoided downstream treatments.

Researchers sometimes also confuse budget impact analysis with cost effectiveness analysis. BIA asks "how much will it cost?" while CEA asks "is it worth the cost?" The two analyses address different questions and serve different decision making needs. Finally, using the wrong perspective (for example, using a societal perspective when the decision maker is a hospital budget holder) produces results that do not answer the relevant question.

A national health ministry evaluates the budget impact of adding a new hepatitis C antiviral to the national formulary. The analysis estimates that 45,000 patients are currently eligible for treatment and expects 6,000 of them to be treated in year one, 10,000 in year two, and 12,000 in year three. At 25,000 USD per course, drug spending is 150 million USD, 250 million USD, and 300 million USD in those years. Savings from avoided cirrhosis care and liver complications grow as more patients are cured, reaching 4 million USD, 12 million USD, and 24 million USD, so the net budget impact is 146 million USD in year one, 238 million USD in year two, and 276 million USD in year three. Costs are not discounted, because the ministry needs to know the cash it must find each year.