A Markov computer simulation model of the economics of neuromuscular blockade in patients with acute respiratory distress syndrome

BACKGROUND: Management of acute respiratory distress syndrome (ARDS) in the intensive care unit (ICU) is clinically challenging and costly. Neuromuscular blocking agents may facilitate mechanical ventilation and improve oxygenation, but may result in prolonged recovery of neuromuscular function and acute quadriplegic myopathy syndrome (AQMS). The goal of this study was to address a hypothetical question via computer modeling: Would a reduction in intubation time of 6 hours and/or a reduction in the incidence of AQMS from 25% to 21%, provide enough benefit to justify a drug with an additional expenditure of $267 (the difference in acquisition cost between a generic and brand name neuromuscular blocker)? METHODS: The base case was a 55 year-old man in the ICU with ARDS who receives neuromuscular blockade for 3.5 days. A Markov model was designed with hypothetical patients in 1 of 6 mutually exclusive health states: ICU-intubated, ICU-extubated, hospital ward, long-term care, home, or death, over a period of 6 months. The net monetary benefit was computed. RESULTS: Our computer simulation modeling predicted the mean cost for ARDS patients receiving standard care for 6 months to be$62,238 (5% – 95% percentiles $42,259 –$83,766), with an overall 6-month mortality of 39%. Assuming a ceiling ratio of $35,000, even if a drug (that cost$267 more) hypothetically reduced AQMS from 25% to 21% and decreased intubation time by 6 hours, the net monetary benefit would only equal $137. CONCLUSION: ARDS patients receiving a neuromuscular blocker have a high mortality, and unpredictable outcome, which results in large variability in costs per case. If a patient dies, there is no benefit to any drug that reduces ventilation time or AQMS incidence. A prospective, randomized pharmacoeconomic study of neuromuscular blockers in the ICU to asses AQMS or intubation times is impractical because of the highly variable clinical course of patients with ARDS

CONTRIBUTIONS OF NUTRITION VERSUS HYPOXIA TO GROWTH IN RURAL ANDEAN POPULATIONS

Previous research on diet and nutrition among peasant agriculturalists in the Andes has produced inconsistent results. As a consequence it has been difficult to determine the extent to which nutritional factors contribute to the slowed, prolonged growth and resultant small adult body size that is characteristic of these highland populations. The study examines patterns of diet and growth in the rural highland community of Nuñoa, Peru (elevation 4,000 m), and compares them to similar data collected on this community during the 1960s. Additional data from other locations in the Andes are then evaluated to discern critical determinants of growth variation. Analyses of the Nuñoan data indicate that nutritional factors have played a significant role in shaping statural growth at this location. Comparisons of other growth surveys indicate that Nuñoans remain among the smallest of all Andean populations. Additionally, urban/rural differences in growth are quite evident in the highlands, with the magnitude of this difference being greater than in other regions (i.e., coastal or jungle). It appears that income level and access to land strongly interact to direct and constrain food consumption patterns. The resulting differences in nutrition, in turn, appear to be strong predictors of growth variation. Consequently, studies that consider 1) dietary intake, 2) level of variability in diet, and 3) relative contributions of purchased and home-produced food to diet should contribute to furthering our understanding of growth variation in the Andes