Week 8 - Evidence-based practice prognosis

Question 1

What are the 5 steps of prognosis?

Answer 1

1. Ask answerable clinical questions about prognosis
2. Track down the evidence
3. Find out if you can believe the study of prognosis
4. Find out what the study of prognosis is telling you
5. Apply the results to pt: advise them/their parents about their prognosis

Question 2

List the 3 factors your should specify when asking answerable clinical questions.

Answer 2

1. population or condition of interest
2. outcome of interest
3. time frame of interest

Question 3

Give an example of a good clinical questions about prognostic factors

Answer 3

For an obese (prognostic factor) 12 year old boy with stress fracture of the tibia (population) what is the likelihood (risk) of returning to soccer (outcome) within 3 months (time frame)?

Question 4

What are the 2 main types of cohorts in prognosis studies and define each?

Answer 4

1. Survivor cohort - a sample of the population of all people with condition, including those with long-standing problems (population had condition different lengths of time)
2. Inception cohort - A sample of the population taken at a uniform (often early) point in the course of the disease (more accurate estimate of prognosis)

Question 5

Explain retrospective studies

Answer 5

Using data base of medical record to see outcomes and prognosis. Loss to follow up cannot usually be calculated

Question 6

How is prognosis expressed in continuous outcomes and give an example

Answer 6

expressed in terms of magnitude such as pain intensity

Question 7

How is prognosis expressed in dichotomous outcomes and give an example

Answer 7

expressed as risk of an event such as recovered vs. not recovered

Question 8

Define Survival curves

Answer 8

Modeling of an event or endpoint against time (ie. injury, recovery, return to work)

Question 9

Define prognostic Factors

Answer 9

Characteristics that are likely to make prognosis much better or worse than average

Question 10

How can we determine which factors influence prognosis and explain

Answer 10

high quality research - help estimate how much the presence of particular prognostic factor modifies prognosis and generate more precise estimates of the prognosis

Question 11

What is one of the most important determinants of patient satisfaction in patient care?

Answer 11

Interpersonal relationship between therapist and patient which involves the ability to communicate effectively with sensitivity

Question 12

What are 2 types of questions about prognosis?

Answer 12

1. Outcome expected

2. Prognositc factors / patients characteristics

Question 13

What are the main factors to specify when asking about prognosis? (3)

Answer 13

• POT*
  1. Population or condition
  2. Outcome of interest
  3. Time frame

Question 14

What is the ideal type of study to get prognosis?

Answer 14

Prospective cohort studies

Question 15

Define prospective cohort study

Answer 15

Longitudinal study that follows over time a group of similar individuals (cohort) who differ with respect to certain factors under study, to determine how these prognostic factors affect rates of certain outcomes.

Question 16

What database is best to use for tracking down evidence for prognosis?

Answer 16

PubMed

Question 17

What are the 3 criteria for a believable study of prognosis?

Answer 17

SIF

1. sampling from a well-defined (target) population?
2. inception cohort?
3. complete/near-complete follow-up?

Question 18

Was is the equation to find the 95% CI of continuous outcomes?

Answer 18

95% CI = mean +/- 3 x SD//2N

Question 19

Define odds ration in prognostic factor studies

Answer 19

Odds of the event happening in the group with the prognostic factor comported with the odds of the event happening in the group without the prognostic factor (ie. parents not being compliant)
= 1, event is equally likely (no affect of prognostic factor)
>1, event is likely to occur in group with prognostic factor
<1, the event is less likely to occur in group with prognostic factor

Question 20

What difference can prognostic information make to clinical practice? (2)

Answer 20

1. Inform patients/parents likely outcome of condition based on evidence
2. Use information to guide clinical decision making about treatment (poor vs. good prognosis tells us whether use treatment or let it take natural history or clinical course)