INTEGRATIVE CARE 10/8b Principles of Measurement

Question 1

questions of measurement

Answer 1

• how good is it?

- what can I get out of it?

Question 2

levels of measurements

Answer 2

counting

mathematical

Question 3

counting measurements

Answer 3

• nominal (names): putting a person in a “bin” (sex, falls risk/not falls risk, race insurance, medications, frequencies, tallies, counts, percentage, mode, bar graph)
• ordinal: bins that have order (MMT, Fim scale for assistance, BMI, amount of comorbidities, all of nominal, central tendency is mode and median, range, bar graphs, pie charts)

Question 4

mathematical measurements

Answer 4

• interval: has order and equal intervals (weight, can have a negative measurement, all ordinal, mean, standard dev, can create MDC)
• ratio: has order, interval, and true 0 (TUG, ROM, Goniometry, Heart Rate, VO2max, 6MWT, all can have a negative measurement, all ordinal, mean, standard dev, can create MDC)

Question 5

how do SEM and MDC get calculated

Answer 5

• measurement error from reliability coefficients/ICC

- MDC from SEM and CI

Question 6

measurement of error SEM

Answer 6

• every measurement has error
• the error can be caused by the patient, the PT the environment, or the instrument
• we use SEM to get a CI around any measurment

Question 7

Confidence interval

Answer 7

fuzzball around every measurement that puts a number on all of the errors that could happen
95%CI = X +/- ~2SEM
-Need SEM to get this

Question 8

MDC

Answer 8

1. From SEM and CI
2. continuous (interval or ratio) data and precision (accuracy, resolution)
   - Digital: important for rounding
   - Analog: measure as precisely as we can to reduce error
   - Measure HR (in 60s - precise in the level of bpm; in 30s - precise in the level of 2bpm)
   - MDC95 = (CiM95 x SqRt 2) x SEM
3. MDC is dependent on SEM (based on average variability expected around a measurement)
   - var in patient perf
   - var in measurement process
4. specific to ptnt population receiving the measurment
5. MCID = smallest chane that would be important to a patient

Question 9

Reliability

Answer 9

• a value that quantifies the consistency of a tool
• necessary, but not sufficient for a measure to be valid/accurate
• test-retest reliability assumes that multiple measures of an unvarying characteristic should be equal

Question 10

reliability coefficients

Answer 10

ICC = Intraclass Correlation Coefficient

• 0.8 or higher is good, 1 is the best it can be
• not super reliable, should include SEMs, SDs, and MDCs because ICCs can be deceiving
• ICC= (variability between subjects - variability within subjects)/variability between subjects
• want a more variable group to get a higher ICC number

Question 11

1s vs ks and 2 vs 3 in ICC

Answer 11

1 (just measured once) vs k (measured multiple tiems and took an average)
2 (generalizable) vs 3 (done with extreme training and intra-rater reliability)

Question 12

Inter rater

Answer 12

between raters

Question 13

intra rater

Answer 13

a single rater