Meaning and Change in Physical Performance

1. Meaning and Change in Physical Performance How can we infuse geriatric thinking into health care? My experience with mobility as an indicator of function

2. Inside every older person is a younger person�.  wondering what the hell happened.� ~Jennifer Yane

3. Goal: Integrate function into usual care of older adults Rationale*: directs immediate service needs helps summarize total burden of disease detects change in status predicts tolerance to stressful health events Predicts future status of everything�

4. Challenges busy clinical care often driven by quick triage based on numbers current function interviews may be long and qualitative for clinicians no diagnostic codes providers, patients and families have been acculturated to think in diagnostic terms

5. Strategy take lay meaning and turn it into numbers make numbers interpretable provide simple numbers to patients and providers let patients and providers internalize meaning Why numbers???

6. Why Numbers? Doctors feel comfortable with them Perceptions of medicine and technology Improves calibration of impressions between observers Commonly used numbers can drive provider and patient behavior: blood pressure, blood sugar, body weight

7. Aging and mobility: a rationale An 86 year old widowed woman is followed in your clinic for hypertension, diabetes, osteoarthritis, and mild renal insufficiency .

8. Mobility as one summary indicator of function Transfers and walking are core self care activities Many other self care activities like dressing and bathing are heavily influenced by mobility Many household management activities are heavily influenced by mobility

9. Significance of Mobility Problems of Aging Ubiquitous Disabling Constraining Distressing Increase need for help by others

10. Meaning and Mobility: the public Books Movies Common language of illness and recovery �slowing down� �still has a spring in his step�

13. Meaning and mobility: providers Global health status and QOL indicators: SF 36 Euroqol Disease specific indicators: heart stroke cancer Parkinson�s disease

14. Mobility as a good geriatric indicator Extensive epidemiological literature re ability to predict functional decline, mortality, utilization, falls Extensive biomechanical and physiological literature re mechanisms, alterations with age and disease Brief assessment is feasible in the clinical setting ? A �vital sign� Efficiency and utility of screening in clinical populations? How to interpret results clinically?

15. Challenges: a complex topic into a simple indicator? Mobility is a complex phenomenon-simple indicators miss much important information Providers use other simple indicators: blood pressure, pulse, weight� Can very brief mobility indicators be a �foot in the door�?

16. The meaning of a gait velocity

17. The meaning of a gait velocity

18. Challenges- no common standards Velocity: meters/second, feet per second, miles per hour Time: 10 feet, 4 meters, 10 meters, 50 feet walk Distance: 6 minute walk, 400 meter walk Metrics rarely translated Lack of overt link to meaning

19. Translating walking speed: making the numbers mean something Meters per second= miles per hour 

20. Translating walking speed: making the numbers mean somethingwalking speed, METS and function

21. Translating walking speed: making the numbers mean somethingwalking speed and 6 minute walk test

26. Mobility measures to describe research populations

27. Mobility measures in routine primary care 14 Primary care offices: space available, staff can perform during routine care Gait speed measure takes < 2 minutes during intake as part of �vital signs�. Reliability comparable to slightly worse than BP coefficient of variation interobserver test-retest 4.5% gait 3.0% DBP 15% gait, 10% DBP

28. Mobility performance as a baseline predictor of future status Mobility measures: gait speed SPPB: 12 point Short Physical Performance Battery (gait speed, timed chair rise, tandem stands) Explain current and future function Predict utilization Predict survival

30. Moving beyond baseline: meaningful change in performance How much change matters? What is a reasonable gold standard? statistical? distal events? patient opinion? provider opinion?

31. One year change rates based on two methods: annual (two time points) or quarterly (every 3 months for one year)

32. Statistical distribution approaches to the definition of meaningful change Effect size: given sample distributions, estimate magnitude of measure change Standard error of the mean Challenges: influenced by sample heterogeneity, assumes symmetric decline and improvement

33. Anchor based method-individual change Use �gold standard� self, significant other or provider estimates Two methods: transition: �better/same/worse� repeated current state: use self-estimate at two time points. Compare mean performance change in those who report change vs those who don�t Challenges: direction of change, thresholds, nonlinearities, response shift, poor association between transition form and repeated current status form

34. Meaningful change in gait speed (m/sec) using several methods and data sets

35. Meaningful change in 6 minute walk and SPPB using several methods and data sets

36. Intervention effects in recent clinical trials: can use proportions to determine NNT

37. Provider anchors: estimates of meaningful change in a frailty study Prospective cohort study of geriatricians and their patients. Geriatricians assess change in frailty during routine clinic visits every 6 months. Instrument developed from patient, caregiver and geriatrician priorities. Scale runs from 1 (marked improvement) to 7 (marked worsening). Structured global assessment format includes 6 �intrinsic� domains (CGIF-Int) and 13 overall domains (CGIF-All). Patients have home assessments by research staff every 6 months for manifestations of frailty (impairments, functional limitations, disability, health status).

38. Provider estimates of meaningful change: frailty studyPreliminary findings 23 geriatricians (43% female) 237 patients (mean age 80, 78% female, 15% non-white). Frailty by geriatrician CGIF-Int worsened in 31 %, improved in 16% and did not change in 53%. Similar effects for CGIF-All

39. Factors that Influenced Geriatrician�s Rating of Change in Frailty

40. Factors that influenced geriatrician�s ratings of frailty

43. Change as an independent predictor of survival Assess the magnitude and patterns of change over one year in 6 measures of health and function estimate effects on five or seven year survival.

45. PEP study: monitor change every three months in index year, then assess survival over subsequent years

48. Transient and Persistent Changeadjusted for age, gender, number of comorbid domains and baseline status

49. Mortality Rates Among Groups with No Decline, Transient Decline and Persistent Decline

50. One year improvement and 5 year survival

51. Improvement and Survival (gait speed) (gait speed ever improved 0.1 m/s compared to baseline, subsequent 7 year survival)

52. 0.1 m/s improvement in baseline slower walkers (<.89 m/s)

53. 0.1 m/s improvement in baseline faster walkers >.89 m/s

54. Bidirectional assessment: no change, improvement, decline, and mixed improvement/decline

55. Patient experience and daily activity: another way to count Restricted activity days are a powerful indicator of health and prognosis (Gill, Nevitt) Restricted activity has high potential for meaning among patients May be useful in conditions with periods of inactivity eg cancer treatment, COPD or CHF exacerbations, recovery from disabling events like hip fracture, stroke

56. High frequency low burden indicator of daily activity:�days in state� Five item daily diary: half day out of bed left home without help difficulty with daily activities difficulty moving around fatigue Pilot testing in our ongoing cohort study for initial standards, also in older cancer treatment patients

57. Baseline characteristics

58. Effect of baseline ECOG score on status at 6 weeks

59. Conclusions Meaning of measures and concepts is based on personal familiarity, experience Mobility status can reflect the experience of patients and providers with current states and with transitions of health and function Simple measures of mobility performance (and maybe counts of daily activity) may be useful for translating experience into meaningful numerical indicators

60. Where are we? We can define preliminary thresholds and magnitudes of meaningful change for gait speed, 6 minute walk distance and possibly SPPB

61. Future Directions: measures Utility of mobility states with M Goldstein (Palo Alto VA and Stanford) Use thresholds and magnitudes of change in our clinical trials to generate NNTs Estimate prognosis of change against future utilization and function Examine subgroup effects: baseline status, age, gender� on change effect sizes Further studies with daily activity indicators

62. Future Directions: applications Differential diagnosis of mobility and balance disorders Intervention studies- common data set across Pitt Pepper Studies Feedback and self-monitoring of gait speed? (for healthy aging: like weight, blood pressure, blood sugar)

65. How old would you be if you didn't know how old you were?� ~Satchel Paige