Can Universal Screening for rare conditions ever be cost-effective? The case of Newborn Screening for Biliary Atresia

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1 Can Universal Screening for rare conditions ever be cost-effective? The case of Newborn Screening for Biliary Atresia Lisa Masucci 1, Stirling Bryan 1, Janusz A. Kaczorowski 3, Jean-Paul Collet 2, Richard A. Schreiber 2 1 Centre for Clinical Epidemiology & Evaluation, Vancouver Coastal Health Research Institute 2 Department of Pediatrics, University of British Columbia 3 Department of Family and Emergency Medicine, University of Montreal CADTH Symposium, April 16 th, 2012

2 Background Biliary Atresia (BA) a newborn liver disease, is the most common cause of end-stage liver disease and liver transplantation in children. BA manifests in the first month of life with jaundice and pale (acholic) stools. Left untreated BA leads to death from liver failure by 2 years of age (Utterson et al. 2005) The incidence of BA in Canada is 5.25/100,000 births (Schreiber et al. 2007)

3 Background The current treatment for BA is sequential surgery: first a Kasai Portoenterostomy (KP) followed by liver transplantation for those cases who still progress to liver failure. The child s age at the time of the KP is the most important prognostic factor for a successful outcome. If the KP is performed in the first 2 months of life it can restore bile flow and may decrease or obviate the need for a liver transplant. In order to detect BA early, Japan and Taiwan have introduced a home-based screening program using a stool color card. The sensitivity and specificity of the stool color card are 97.1% and 99.9%, respectively (Hsaio et al.2008; Chen et al.2006). This color card is currently not used in Canada.

4 Home-based Stool Color Card

5 Objectives To determine if a universal home-based stool color card program in Canada is cost-effective Outcomes: incremental cost, life years gained, and ICER ICER: Costs Intervention Costs Usual Care Outcomes Intervention Outcomes Time horizon: 10 years Usual Care Cost perspective: publicly funded health care system Our assumed willingness to pay threshold was $50K per life year gained

6 Methods: Overview of screening strategies No Universal Screening Disease progression with current guidelines. No Screening Universal Screening (passive) Stool card included in package handed at discharge Universal Screening (reminder) Passive strategy + reminder card sent to parents in the third week

7 Methods Model: Combined decision tree and Markov model Modeling age at Kasai and Liver Transplantation Annual cycle lengths Costs in 2011 Canadian dollars, discounted at 5% Probabilistic Analysis Monte Carlo simulation Sampling 10,000 times

8 Methods: Sensitivity analyses Sensitivity analyses performed to assess the robustness of results to variation in: Administrative cost Card utilization rate Liver transplantation cost Stool color card sensitivity and specificity

9 Model Structure

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11 Methods: Parameters (Probabilities) BA Passive Distribution (Jan 2011-Aug 2011) Reminder Letter (Jan 2011-Aug 2011) Card Utilization (pilot project results) Card Return (pilot project results) BA+ Card Utilization (pilot project results) Card Return (estimated from Taiwan study)

12 Item Overall Probability Probability by age Kasai procedure with Stool Color Card Kasai days after birth days after birth days after birth days after birth 0 Kasai procedure w/o Stool Color Card Kasai days after birth days after birth days after birth days after birth 0.18

13 Methods: Parameters (Probabilities) Survival with Native Liver Age at Kasai End of yr 2 End of yr 5 End of yr days after birth days after birth days after birth days after birth

14 Methods: Parameters (Probabilities) Item Probability Waiting for Liver Transplant Die on Waiting List 0.08 Remain Waiting 0.12 Undergo First Liver Transplant 0.80 Post Liver Transplant 1 Graft survival (stable) 0.86 Death first year post LT 0.10 Death subsequent years Await Liver Transplant 2 Receive 2 nd Liver Transplant 0.60 Die 0.40

15 Methods: Parameters (Costs) Item Passive Strategy Administration Card Card Return Postage Reminder Card Strategy Administration Reminder Letter Annual Costs $0.63 $0.42 $0.53 $0.84 $0.94 Post Screening Visit to determine if Patient has BA $737 Kasai Portoenterostomy $23,466 After Kasai, Alive with no liver transplant $1,703 Awaiting Liver Transplant Liver Transplant Assessment (one time) Physician Appointments (continuous) Liver Transplant Organ Procurement + Liver Transplantation (one time) Physician Visits + Medications + Laboratory Tests $2,037 $2,827 $452,635 $7,332

16 Results Per 381,400 births in Canada # False Positives # Kasai # Liver Transplants Universal Screening (passive) Universal Screening (reminder) No Universal Screening

17 Results: Probabilistic Analysis Per 381,400 births in Canada Strategy Δ Cost Δ Life years gained ICER ΔC/ΔE No Screening Passive Screening Screening with Reminder $204,588 9 years $22,732 $429,785 2 years $214,892 Interpretation: Passive screening is highly cost-effective (i.e. well below the threshold ICER of $50k) but screening with a reminder is not even close to being cost-effective (i.e. well above the $50k ICER)

18 Cost-effectiveness acceptability curve

19 Sensitivity Analysis: passive screening Administration cost of passive screening Base case value: $0.63 per child screened If the admin cost for passive screening is as high as $1 per child then ICER is still below $50k. Card utilization rate with passive screening Base case value: 0.75 If the card utilization rate for passive screening is as low as 0.40 then ICER still below $50k.

20 Sensitivity Analysis The model results were not highly sensitive variations in test sensitivity or liver transplantation cost If test sensitivity is assumed to be as low as 67%, the passive screening remains cost-effective ($38,503 per life year gained) If the cost per liver transplant is reduced to $190,000 passive screening is still cost-effective. The model results were sensitive to variations in test specificity If the test specificity dropped to 98% the screening strategy was no longer cost-effective.

21 Discussion Overall conclusion: BA screening using a passive strategy looks potentially very attractive from a cost-effectiveness perspective but screening with follow-up and reminders does not. Limitations: Estimates for second liver transplant Screening program may not be representative of general population of Canada Card return rates for BA positive patients were taken from a Taiwanese study

22 Thank you Comments, questions?