Probabilistic mapping of descriptive health status responses onto health state utilities using Bayesian networks: an empirical analysis converting SF-12 into EQ-5D utility index in a national US sample

Med Care. 2011 May;49(5):451-60. doi: 10.1097/MLR.0b013e318207e9a8.


Background: As quality-adjusted life years have become the standard metric in health economic evaluations, mapping health-profile or disease-specific measures onto preference-based measures to obtain quality-adjusted life years has become a solution when health utilities are not directly available. However, current mapping methods are limited due to their predictive validity, reliability, and/or other methodological issues.

Objectives: We employ probability theory together with a graphical model, called a Bayesian network, to convert health-profile measures into preference-based measures and to compare the results to those estimated with current mapping methods.

Methods: A sample of 19,678 adults who completed both the 12-item Short Form Health Survey (SF-12v2) and EuroQoL 5D (EQ-5D) questionnaires from the 2003 Medical Expenditure Panel Survey was split into training and validation sets. Bayesian networks were constructed to explore the probabilistic relationships between each EQ-5D domain and 12 items of the SF-12v2. The EQ-5D utility scores were estimated on the basis of the predicted probability of each response level of the 5 EQ-5D domains obtained from the Bayesian inference process using the following methods: Monte Carlo simulation, expected utility, and most-likely probability. Results were then compared with current mapping methods including multinomial logistic regression, ordinary least squares, and censored least absolute deviations.

Results: The Bayesian networks consistently outperformed other mapping models in the overall sample (mean absolute error=0.077, mean square error=0.013, and R overall=0.802), in different age groups, number of chronic conditions, and ranges of the EQ-5D index.

Conclusion: Bayesian networks provide a new robust and natural approach to map health status responses into health utility measures for health economic evaluations.

MeSH terms

  • Bayes Theorem
  • Health Expenditures / statistics & numerical data
  • Health Status*
  • Health Surveys
  • Humans
  • Least-Squares Analysis
  • Logistic Models
  • Models, Statistical
  • Monte Carlo Method
  • Quality-Adjusted Life Years*
  • Surveys and Questionnaires
  • United States / epidemiology