1. Case 1 of 2 : Cost-Effectiveness Analysis (CEA): In Wu et al. (2006) researchers performed an analysis to evaluate the cost-effectiveness of doing stool DNA testing in addition to other types of traditional screenings, i.e., fecal occult blood testing annually, flexible sigmoidoscopy or colonoscopy, every 5 and 10 years for colorectal cancer in countries where colon cancer prevalence is low. Also, evaluated was the cost/benefit of doing no screenings (Wu, 2006).
The subjects were people 50 to 75 years of age in Taiwan. The researchers used the annual cost of $13,000 per life-year saved (which is roughly the per capita GNP of) as the ceiling ratio for assessing whether DNA testing was cost-effective (Wu, 2006).
Simulated results for screening strategies to prevent Colon Rectal Cancer (CRC)
Variable Screening Strategy
No Screening DNA (3yrs) DNA (5yrs) DNA (10yrs) Occult Blood Flexible Sigmoid. (5yrs) Colonoscopy (10 yrs)
a. Total cases of CRC, n 2,917 2,435 2,654 2,710 2,129 2,253 1,780
b. CRC deaths, n 1,729 1,345 1,467 1,574 1,059 1,328 1,077
c. Perforation deaths, n 0 3 2 1 5 3 12
e. Reduction in CRC incidence, % 0 17 9 7 27 23 39
f. Reduction in CRC mortality, % 0 22 15 9 39 23 39
g. Life expectancy, year 15.7337 15.7476 15.7434 15.74 15.7584 15.7477 15.759
h. Total costs, thousand $ 22,022 35,637 31,077 26,856 19,824 24,909 21,843
i. Incremental life-year saved, year 0 1,390 970 626 2,464 1,383 2,530
j. Incremental cost, thousand $ 0 13,615 9,054 4,834 -2,198 2,887 -180
k. Incremental cost ($)/life-years saved compared with no screening 0 9,794 9,335 7,717 Dominant ‡ 2,087 Dominant †
* Values obtain from a cohort of 100,000 persons 50 years of age who were followed for 25 years.
† The other screening strategy is more effective and less costly than stool DNA testing strategy.
‡ The screening is more effective and less costly than No Screening.
Adapted from: Wu et al. BMC Cancer 2006 6:136 doi:10.1186/1471-2407-6-136
Wu, Grace HM. Wang, Yi-Ming . Yen, Amy MF. Wong, Jau-Min Lai, Hsin-Chih Warwick, Jane and Chen, Tony HH. (2006) Cost-effectiveness analysis of colorectal cancer screening with stool DNA testing in intermediate-incidence countries. BMC Cancer 2006, 6:136 doi:10.1186/1471-2407-6-136
QUESTIONS: In your own words and
1) From the research results shown in the chart above, which type of screening had the highest and which had the lowest reduction in colon-rectal cancer mortality?
2) How do you interpret the findings (Conclusion) in regard to the A-K results in regard to the cost/effectives of doing DNA-testing at 3 years, 5 years, 10 years, or not doing DNA tests at all?
NOTE: Essay Question is in 2 parts. This is Part 1 to be completed and then go <next>, to Part 2 and complete it.
Case #2 of 2: Cost/Benefit literature review for vaginal birth after cesarean (VBAC)
A client had a cesarean delivery in a hospital setting for breech presentation with her first pregnancy. She is pregnant again and after exploring her delivery options, has decided she wants to attempt a vaginal birth after cesarean (VBAC). She has had an uncomplicated pregnancy this time and the fetus is not breech. The same OB-GYN will be assisting in her delivery. The OB-GYN performs a systematic review of the literature to assess the benefits and harms of VBAC versus repeat cesarean delivery.
Part 1 of 2: Researching Empirical Evidence
1. What kinds and sources of data does the OB-GYN need to review in order to make a rational clinical planning decision?
2. Which types of studies available on this topic would be the most useful in clinical decision making?
3. What types of studies would you want to exclude?
4. Why would there be a lack of randomized clinical trials (RCT’s) available to address this clinical question?
2. NOTE: This is Part 2 of the final essay question: The last essay question requires you to do a 2×2 table in addition to calculations. The tables may be done by copying the table from the question directly into your answer and then filling the table out.
Case: Calculating Odds Ratio
In planning for her delivery, the client reads about birthing centers and asks the midwife if it is safe to have a VBAC in a freestanding birthing center. The midwife reviews the data from national studies of VBACs in birthing centers compared to VBACs in hospital settings and obtains the following statistics to aid her in clinical decision making:
N= 1913 Birthing Center based VBAC Rates
• 87% delivered vaginally
• 24% of women were transferred to the hospital prior to delivery
• There were 25 women who experienced a serious adverse outcome (of which 6 were uterine rupture)
• There were 7 perinatal deaths (0.5%)
• There were 15 infants with low apgar scores (below 7) after 5 minutes of life (1.0%)
N= 1913 Hospital based VBAC Rates (Control)
• 76% delivered vaginally
• There were 32 women who experienced a serious adverse outcome (of which 15 were uterine ruptures)
• There were 3 perinatal deaths
• There were 2 infants with low apgar scores (less than 7) after 5 minutes of life
(Part 2 of 2): Construct the following for 1 and 2 and answer question 3
1. Construct a 2 x 2 table, calculate, and interpret the odds ratio of women who suffered a serious adverse outcome from attempting a VBAC delivery in order to estimate the relative risk to a mother delivering VBAC in midwifery based freestanding birthing centers. Cases are those with a serious outcome, controls are those without. The exposure is treatment in a birthing center. The not exposed group is treatment in a hospital.
Exposure Cases Controls
2. Construct a 2 x 2 table, calculate, and interpret the odds ratio of infants who suffered a serious adverse outcome (including death) from attempting a VBAC delivery in order to estimate the relative risk to an infant delivered VBAC in midwifery based freestanding
3. What does the midwife conclude regarding the safety to mother and baby by attempting a VBAC in midwifery based birthing centers? What clinically is the best decision for this client and her unborn baby?