Appendix A: General Scheme of a Cost Utility Analysis Economic Example Evaluation Steps 1. Ask a clear What is the more cost-effective procedure: the Deep Inferior study question Epigastric Perforator Flap (DIEP) or Free Transverse Rectus Abdominis Myocutaneous (TRAM) Flap for postmastectomy reconstruction? 2. Determine Third-party payer (Ministry of Health for Ontario) perspective to be used 3. Calculate direct Direct medical costs taken from the third-payer perspective costs associated (surgical fees, anesthetist’s fees, hospital charges) from the with the two Ontario Ministry of Health Schedule of Benefits procedures 4. Review For example, total/partial flap failure, hernia, abdominal wall literature to weakness, fat necrosis, hematoma as well as the health state of identify all “successful surgery”. complications (health states) associated with these procedures and treatment of these procedures 5. Identify the For example the expected cost of for a hernia: 0.2 (probability probabilities and of a complication occurring) x 0.04 (probability of a hernia cost of each occurring) x estimated cost ($1663.48) to give an expected cost complication = $13.31 (costs derived from the Ontario Ministry of Health Schedule of Benefits). 6. Design a Examples of two decision trees: decision tree with branches showing health states and the probability of each 7. Measure utility To determine utilities of various health states associated with and QALY for DIEP and free TRAM flaps, 32 plastic surgeons across Canada each complication were asked to rank their preference using a ‘feeling pathway thermometer’ (10 cm vertical ladder with 0 = death; 1 = perfect health). Successful surgery was determined to have a utility of 0.87. QALY was calculated using a hypothetical patient of 45 years with life expectancy of 78.6 years (statistic from Statistics Canada).
Appendix A: General Scheme of a Cost Utility Analysis Economic Evaluation Steps Example 1. Ask a clear study question What is the more cost-effective procedure: the Deep Inferior Epigastric Perforator Flap (DIEP) or Free Transverse Rectus Abdominis Myocutaneous (TRAM) Flap for postmastectomy reconstruction? 2. Determine perspective to be used Third-party payer (Ministry of Health for Ontario) 3. Calculate direct costs associated with the two procedures Direct medical costs taken from the third-payer perspective (surgical fees, anesthetist’s fees, hospital charges) from the Ontario Ministry of Health Schedule of Benefits 4. Review literature to identify all complications (health states) associated with these procedures and treatment of these procedures For example, total/partial flap failure, hernia, abdominal wall weakness, fat necrosis, hematoma as well as the health state of “successful surgery”. 5. Identify the probabilities and cost of each complication For example the expected cost of for a hernia: 0.2 (probability of a complication occurring) x 0.04 (probability of a hernia occurring) x estimated cost ($1663.48) to give an expected cost = $13.31 (costs derived from the Ontario Ministry of Health Schedule of Benefits). 6. Design a decision tree with branches showing health states and the probability of each Examples of two decision trees: 7. Measure utility and QALY for each complication pathway To determine utilities of various health states associated with DIEP and free TRAM flaps, 32 plastic surgeons across Canada were asked to rank their preference using a ‘feeling thermometer’ (10 cm vertical ladder with 0 = death; 1 = perfect health). Successful surgery was determined to have a utility of 0.87. QALY was calculated using a hypothetical patient of 45 years with life expectancy of 78.6 years (statistic from Statistics Canada).
PRS_132_1_2013_05_30_THOMA_205513_SDC1.docx