Showing papers by "James F. Fries published in 2014"

Do Workplace Health Promotion (Wellness) Programs Work

Abstract: Objective: To respond to the question, “Do workplace health promotion programs work?” Methods: A compilation of the evidence on workplace programs’ effectiveness coupled with recommendations for critical review of outcome studies. Also, reviewed are recent studies questioning the value of workplace programs. Results: Evidence accumulated over the past three decades shows that well-designed and well-executed programs that are founded on evidence-based principles can achieve positive health and financial outcomes. Conclusions: Employers seeking a program that “works” are urged to consider their goals and whether they have an organizational culture that can facilitate success. Employers who choose to adopt a health promotion program should use best and promising practices to maximize the likelihood of achieving positive results.

Item Response Theory, Computerized Adaptive Testing, and PROMIS: Assessment of Physical Function

Abstract: Objective. Patient-reported outcome (PRO) questionnaires record health information directly from research participants because observers may not accurately represent the patient perspective. Patient-reported Outcomes Measurement Information System (PROMIS) is a US National Institutes of Health cooperative group charged with bringing PRO to a new level of precision and standardization across diseases by item development and use of item response theory (IRT). Methods. With IRT methods, improved items are calibrated on an underlying concept to form an item bank for a “domain” such as physical function (PF). The most informative items can be combined to construct efficient “instruments” such as 10-item or 20-item PF static forms. Each item is calibrated on the basis of the probability that a given person will respond at a given level, and the ability of the item to discriminate people from one another. Tailored forms may cover any desired level of the domain being measured. Computerized adaptive testing (CAT) selects the best items to sharpen the estimate of a person’s functional ability, based on prior responses to earlier questions. PROMIS item banks have been improved with experience from several thousand items, and are calibrated on over 21,000 respondents. Results. In areas tested to date, PROMIS PF instruments are superior or equal to Health Assessment Questionnaire and Medical Outcome Study Short Form-36 Survey legacy instruments in clarity, translatability, patient importance, reliability, and sensitivity to change. Conclusion. Precise measures, such as PROMIS, efficiently incorporate patient self-report of health into research, potentially reducing research cost by lowering sample size requirements. The advent of routine IRT applications has the potential to transform PRO measurement.

Extending the Floor and the Ceiling for Assessment of Physical Function

Abstract: Objective To improve the assessment of physical function by enhancing precision of physical function assessment as it pertains to subjects at extreme ends of the health continuum (i.e., subjects with extremely poor function [“floor”] or extremely good health [“ceiling”]). Methods Under the Patient-Reported Outcomes Measurement Information System (PROMIS) (a National Institutes of Health initiative), we developed new items to assess floor and ceiling physical function in order to supplement the existing item bank. Using item response theory and standard PROMIS methodology, we developed 31 floor items and 31 ceiling items and administered the items during a 12-month prospective, observational study of 737 subjects whose health status was at either extreme. Effect size was calculated and change over time was compared across anchor instruments and across items. Using the observed changes in scores, we back-calculated sample size requirements for the new and comparison measures. Results We studied 444 subjects who had been diagnosed as having a chronic illness and/or were of old age and 293 generally fit subjects (including athletes in training). Item response theory analyses confirmed that the new floor and ceiling items outperformed reference items (P < 0.001). The estimated post hoc sample size requirements were reduced by a factor of 2–4 for the floor population and a factor of 2 for the ceiling population. Conclusion Extending the range of items by which physical function is measured can substantially improve measurement quality, reduce sample size requirements, and improve research efficiency. The paradigm shift from assessing disability to assessing physical function focuses assessment on the entire spectrum of physical function, signals improvement in the conceptual base of outcome assessment, and may be transformative as medical goals more closely approach societal goals for health