How much?

OBJECTIVE: To review critically the statistical methods used for health economic evaluations in randomised controlled trials where an estimate of cost is available for each patient in the study. DESIGN: Survey of published randomised trials including an economic evaluation with cost values suitable for statistical analysis; 45 such trials published in 1995 were identified from Medline. MAIN OUTCOME MEASURES: The use of statistical methods for cost data was assessed in terms of the descriptive statistics reported, use of statistical inference, and whether the reported conclusions were justified. RESULTS: Although all 45 trials reviewed apparently had cost data for each patient, only 9 (20%) reported adequate measures of variability for these data and only 25 (56%) gave results of statistical tests or a measure of precision for the comparison of costs between the randomised groups. Only 16 (36%) of the articles gave conclusions which were justified on the basis of results presented in the paper. No paper reported sample size calculations for costs. CONCLUSIONS: The analysis and interpretation of cost data from published trials reveal a lack of statistical awareness. Strong and potentially misleading conclusions about the relative costs of alternative therapies have often been reported in the absence of supporting statistical evidence. Improvements in the analysis and reporting of health economic assessments are urgently required. Health economic guidelines need to be revised to incorporate more detailed statistical advice.

Cost-Benefit Analysis↗

PubMed1998

Economic evaluation and randomised controlled trial of extracorporeal membrane oxygenation: UK collaborative trial. The Extracorporeal Membrane Oxygenation Economics Working Group.

OBJECTIVE: To compare the resource implications and short term outcomes of extracorporeal membrane oxygenation and conventional management for term babies with severe respiratory failure. DESIGN: Cost effectiveness evaluation alongside a randomised controlled trial. SETTING: 55 approved recruiting hospitals in the United Kingdom. These hospitals provided conventional management, but infants randomised to extracorporeal membrane oxygenation were transferred to one of five specialist centres. SUBJECTS: 185 mature newborn infants (gestational age at birth >35 weeks, birth weight >2 kg) with severe respiratory failure (oxygenation index >40) recruited between 1993 and 1995. The commonest diagnoses were persistent pulmonary hypertension due to meconium aspiration, congenital diaphragmatic hernia, isolated persistent fetal circulation, sepsis, and idiopathic respiratory distress syndrome. MAIN OUTCOME MEASURE: Cost effectiveness based on survival at 1 year of age without severe disability. RESULTS: 63 (68%) of the 93 infants randomised to extracorporeal membrane oxygenation survived to 1 year compared with 38 (41%) of the 92 infants who received conventional management. Of those that survived, one infant in each arm was lost to follow up and the proportion with disability at 1 year was similar in the two arms of the trial. One child in each arm had severe disability. The estimated additional cost of extracorporeal membrane oxygenation per additional surviving infant without severe disability was 51 222 pounds and the cost per surviving infant with no disability was 75 327 pounds. CONCLUSIONS: Extracorporeal membrane oxygenation for term neonates with severe respiratory failure would increase overall survival without disability. Although the policy will increase costs of neonatal health care, it is likely to be as cost effective as other life extending technologies.

Cost-Benefit Analysis↗