- Internal Medicine
- Geriatrics-Elder Care Comprehensive Assessment
Medical Director, Aging Adult Services, Stanford University Hospital (2008 - Present)
Medical Director, Vi, CCRC - Palo Alto (2008 - Present)
Medical Director, Manor Care HCR (2007 - Present)
Committee Member, GRECC Advisory Board Committee (2009 - Present)
Director, Senior Care Center, Stanford University-School of Medicine (2012 - Present)
Board Certification: American Board of Internal Medicine, Geriatric Medicine (2005)
Fellowship: Stanford University and VA Palo Alto Geriatric Medicine Fellowship (2004) CA
Residency: St Mary's Medical Center Internal Medicine Residency (2003) CA
Medical Education: Hahnemann University Medical College (2000) PA
Board Certification: American Board of Internal Medicine, Internal Medicine (2003)
Current Research and Scholarly Interests
Collaborator in the HALF study
Collaborator in the PROMISE study
Primary Investigator, Bidet Pilot Study- 650-644-9230
Graduate and Fellowship Programs
Geriatric Medicine (Fellowship Program)
Extending the floor and the ceiling for assessment of physical function.
Arthritis & rheumatology
2014; 66 (5): 1378-1387
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"]).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.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.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.
View details for DOI 10.1002/art.38342
View details for PubMedID 24782194
View details for PubMedCentralID PMC4012831
- Extending the floor and the ceiling for assessment of physical function. Arthritis & rheumatology (Hoboken, N.J.) 2014; 66 (5): 1378-1387
1extending the floor and the ceiling for assessment of physical function.
Arthritis and rheumatism
Objective. The objective of the current study was to improve the assessment of physical function by improving the precision of assessment at the floor (extremely poor function) and at the ceiling (extremely good health) of the health continuum. Methods. Under the NIH PROMIS program, we developed new physical function floor and ceiling items to supplement the existing item bank. Using item response theory (IRT) and the standard PROMIS methodology, we developed 30 floor items and 26 ceiling items and administered them during a 12-month prospective observational study of 737 individuals at the extremes of health status. Change over time was compared across anchor instruments and across items by means of effect sizes. Using the observed changes in scores, we back-calculated sample size requirements for the new and comparison measures. Results. We studied 444 subjects with chronic illness and/or extreme age, and 293 generally fit subjects including athletes in training. IRT 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 two to four at the floor and a factor of two at the ceiling. Conclusion. Extending the range of physical function measurement can substantially improve measurement quality, can reduce sample size requirements and improve research efficiency. The paradigm shift from Disability to Physical Function includes 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. © 2013 American College of Rheumatology.
View details for DOI 10.1002/art.38342
View details for PubMedID 24403003
- Demystifying Geriatrics Part II: Patient Stratification SGIM forum 2013; 36 (6)
- Demystifying Geriatrics Part I: Stigma and Daily Realities SGIM forum 2013; 36 (6)
Development and assessment of floor and ceiling items for the PROMIS physical function item bank.
Arthritis research & therapy
2013; 15 (5): R144-?
Disability and Physical Function (PF) outcome assessment has had limited ability to measure functional status at the floor (very poor functional abilities) or the ceiling (very high functional abilities). We sought to identify, develop and evaluate new floor and ceiling items to enable broader and more precise assessment of PF outcomes for the NIH Patient-Reported-Outcomes Measurement Information System (PROMIS).We conducted two cross-sectional studies using NIH PROMIS item improvement protocols with expert review, participant survey and focus group methods. In Study 1, respondents with low PF abilities evaluated new floor items, and those with high PF abilities evaluated new ceiling items for clarity, importance and relevance. In Study 2, we compared difficulty ratings of new floor items by low functioning respondents and ceiling items by high functioning respondents to reference PROMIS PF-10 items. We used frequencies, percentages, means and standard deviations to analyze the data.In Study 1, low (n = 84) and high (n = 90) functioning respondents were mostly White, women, 70 years old, with some college, and disability scores of 0.62 and 0.30. More than 90% of the 31 new floor and 31 new ceiling items were rated as clear, important and relevant, leaving 26 ceiling and 30 floor items for Study 2. Low (n = 246) and high (n = 637) functioning Study 2 respondents were mostly White, women, 70 years old, with some college, and Health Assessment Questionnaire (HAQ) scores of 1.62 and 0.003. Compared to difficulty ratings of reference items, ceiling items were rated to be 10% more to greater than 40% more difficult to do, and floor items were rated to be about 12% to nearly 90% less difficult to do.These new floor and ceiling items considerably extend the measurable range of physical function at either extreme. They will help improve instrument performance in populations with broad functional ranges and those concentrated at one or the other extreme ends of functioning. Optimal use of these new items will be assisted by computerized adaptive testing (CAT), reducing questionnaire burden and insuring item administration to appropriate individuals.
View details for DOI 10.1186/ar4327
View details for PubMedID 24286166