Evidence cycle

Ask–acquire–appraise–apply

Hayward’s evidence cycle

Adds in assess

Making a health decision takes what into consideration

Patients circumstance, research evidence, clinical expertise, and patients values/preferences

Background question components

Question + condition

Ex: (what causes) +(Lyme disease)

Foreground question components

“PICO”

Patient +intervention+ comparison + outcome

Diagnostic PICO

P: describe the patient

I: new diagnostic test

C: gold standard test

O: condition to be detected

Prognostic PICO

P: describe patient

I: prognostic factor

C: no prognostic factor

O: health state

Harm PICO

P: describe the patient

I: exposure

C: lack of exposure

O: health state

What is EBCP

Recognize problems, asking questions, evaluating and applying evidence

Clinical research

- offers direct clinical applicability
- designed to replicate authentic/functioning environments
- direct solutions to practical problems
- theory based knowledge

Basic science research

- little clinical relevance
- performed in controlled lab setting
- address theoretical issues

6 Levels of the hierarchy pyramids

- (Lowest-least) in vitro research
- Animal research
- Case series, case studies, surveys
- Cohort studies, case control studies
- RCT
- Meta analyses, systematic reviews

Likelihood of bias

- Systematic reviews
- RCT
- Cohort studies
- Case studies, case series
- (Bottom- most bias) clinical experience

Case control studies or cohort studies

Start with patients who have the disease

Match them with controls

Retrospective

(+) ethnically challenging diseases, rare conditions, limited resources

Best study to show causation

RCT

Meta-analysis or systematic review

Combines the results of many studies

Sensitivity

Probability of a positive test in someone who has the disease

“PID”

In a 4*4 it’s the top left/ total left column

Specificity

Probability of a negative test in someone who doesn’t have the disease

“NIH”

In a 4*4 it’s the bottom right/ total right column

Positive predictive value

Probability that a patient with a positive test really does have the disease

In a 4*4 it’s the top left/ top row

Negative predictive value

The probability that a patient with a negative test really does not have the disease

In a 4*4 it’s the bottom right/bottom row

Positive likelihood ratio

ratio (+in disease/ total in disease)/ (+ no disease/ total no disease)

What are examples of exposures

Survey, file review, interview

Interpretation of + likelihood ratio

1: test is 5 times more likely in patients w/ disease than without

Statistical Test to use if:

Describe one group

Normal: mean, SD

Non-normal: median

Statistical Test to use if:

predict value from another measured variable

normal: simple linear regression or non linear regression

non-normal: non parametric regression

Where do you look for prognostic factors

Table 1

How to detect similar outcome?

Did they use the same method to measure what you are researching

How to find if the follow up sufficiently complete?

Number of starters and follow up with are equal, usually a flow chart

Was there enough time to see factors

Risk ratio, odds ratio?

Rr= times

Odds ratio= association

Paired groups vs unpaired groups

Paired- taking data from 1 patient in two instances, grouping two points of data

Unpaired- not comparing groups of data

Normal distribution of data matches what

A bell curve

T test

Compares two groups

Can be pried or unpaired

Gives t value, but look at p value

P value

Significant significance if p

Mann-Whitney

Difference between 2 unpaired groups

Gives u p r values

Wilcoxon test

Paired groups

ANOVA

Compares 3 or more groups

Report f and p value

Pearson test

Test of association

Spearman

Test of association

Use with non normally distributed data

Linear regression

Asses relationship between 2 or more variables to see if there is a prediction

Doe def

Disease oriented evidence

Poem def

Patient oriented evidence that matters

Doe examples

Insight into patient physiology

Of interest to health provider

BP, reflexes, nervoscope

Poem examples

Self reported by patient

Of interest to patient and clinician

Pain rating, level of function, quality of life

Outcome measure examples

Pain, mental status, disability measurement tool, energy, etc

What type of question do you use to find outcome measure

Background question

Clinimetric properties

Reliability, validity, sensitivity to change, and internal consistency

Don’t try to make up your own outcome measure

Outcome measure for pain

Quadruple vas

NRS

Outcome measure for spine

Oswesty Bourne neck questionnaire Neck disability index Roland Morris scale Headache disability index

Outcome measure for general health

Health status questionnaire

Outcome measure for upper extremity

Upper extremity functional index

Outcome measure for lower extremity

Foot ankle outcome score

Hip dysfunction and osteoarthritis outcome score

Knee and osteoarthritis outcome score

Lower extremity functional scale

Outcomes for general extremity

Rheumatoid and arthritis outcome score

VAS

10 cm line

Please make a vertical line where your pain is at

Vertical VAS works best for who

Elderly

NRS

Scale 1-10

Quadruple VAS

Pain right now?

Typical or average pain?

Pain at its best?

Pain at its worst?

Pain diagrams

Body and you color in where the pain is

ODI

10 sections of daily activity 6 choices in each Scored 0-5 Add each section for overall disability Multiply by 2 for %

NDI

Neck disability

Modified ODI by Howard Vernon

RMQ

Low back disability

24 statements

Bournemouth

7 items

Each on scale of 10

Take total points and divide by 70%

Headache disability index

2 subscales

Emotional and functional

UEFI or LEFI

20 items

Scored 0-4

Total score /80 x 100=%

Score gets higher with lower pain

Foot and ankle, hip dysfunction, knee, RA

6 areas- symptoms, stiffness, pain, ADL, sports/recreation, quality of life

Scored 0-4

Total score /168 x 100=%

Needs a change of 10% for meaningful improvement

General Health Status Questionnaire

8 sub-scales of general health

2 summary measures

overall score

3 individual diagnostic questions

8 sub-scales of general health

physical functioning, role physical, body pain, general health, vitality, social functioning, role emotional, mental health

2 summary measures

Physical health and emotional health