1. Department of Health Services, Boston University School of Public Health, Boston, Mass, Center for Health Quality, Outcomes and Economic Re-search, Bedford VAMC, Bedford, Mass,
2. Department of Health Services, Boston University School of Public Health, Bos-ton, Mass, Center for Health Quality, Outcomes and Economic Re-search, Bedford VAMC, Bedford, Mass
3. Center for Health Quality, Outcomes and Economic Re-search, Bedford VAMC, Bedford, Mass
4. Section of General Internal Medicine, Boston Medical Center, and Boston University School of Medicine, Boston, Mass
5. Department of Health Services, Boston University School of Public Health, Bos-ton, Mass, Center for Health Quality, Outcomes and Economic Re-search, Bedford VAMC, Bedford, Mass, Section of General Internal Medicine, Boston Medical Center, and Boston University School of Medicine, Boston, Mass