Exploring the Effect of Different Patient Entry Intervals on Budget Impact Estimations


Neves C1, Kasle A2, van Keep M1, Matthijsse S3
1Lumanity, Utrecht, NV, Netherlands, 2Lumanity, Las Vegas, NV, USA, 3Lumanity, Utrecht, DBY, Netherlands


Accurate budget impact projections are crucial for decision-making, and population size is important in these analyses. Budget impact analyses generally include open populations, with individuals entering and leaving depending on whether they meet the treatment eligibility criteria, and assume that all patients initiating treatment in a given period (usually a year) enter the analysis at the start of that period. We explored whether more continuous patient entry affects budget impact projections.


A budget impact model using dummy data was developed in Microsoft Excel® to test different patient entry intervals: yearly, quarterly, monthly and weekly. 100–120 patients initiate treatment yearly and are evenly distributed across the quarterly/monthly/weekly intervals within each year. The post-launch uptake of the hypothetical intervention among patients initiating treatment increases from 20% in Year 1 to 70% in Year 3. The intervention is administered every 2 weeks (100/administration), and the comparator is administered every 3 weeks (200/administration). Weekly discontinuation probabilities are 0.99% and 2.28% for the intervention and comparator, respectively.

RESULTS: The cumulative budget impact for Year 1–Year 3 is €53,579, €25,485, €21,072 and €19,347 for the yearly, quarterly, monthly and weekly patient entry intervals, respectively. The difference between annual and weekly patient entry is particularly high for Year 3 (€42,668 versus €22,460). Sensitivity analyses included the cost of subsequent treatment once the intervention or comparator are discontinued, with 3-year cumulative budget impacts of €31,193 and €2,010 for yearly and weekly patient entry, respectively.


The length of patient entry intervals affects budget impact estimates, which can influence reimbursement decisions and price negotiations (e.g. meeting expenditure thresholds associated with the intervention launch). As patients are diagnosed and initiate treatment throughout the year in clinical practice, we suggest using short (e.g. weekly) patient entry intervals in these analyses, ideally reflecting seasonal variations in screening and diagnosis.

Conference/Value in Health Info

2022-11, ISPOR Europe 2022, Vienna, Austria

Value in Health, Volume 25, Issue 12S (December 2022)




Economic Evaluation

Topic Subcategory

Budget Impact Analysis


No Additional Disease & Conditions/Specialized Treatment Areas

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