wk 7- prognostic

Question 1

prognosis questions include

Answer 1

P- paint and specific condition relevant to prognosis
I- intervention
O- outcome
T- time

it is common for questions to just include P and O

Question 2

prognosis hierarchy of evidence

Answer 2

level 1- systematic review of level II studies
level 2- prospective cohort study (0bservational study)
level III-1- not used for a prognostic question?
level III-2 analysis of the prognostic factors among the participants in one group of a RCT (lower on list because of its strict inclusion and exclusion criteria not representing the population)
level III-3 - retrospective cohort study. (incomplete Data risk, selection bias)
Level IV- case series or cohort study where participants are at different stages of the condition or disease

Question 3

inception cohort is?

Answer 3

group of participants are enrolled in the study at the onset or very early in the progressing of their condition.

Question 4

where to search for prognostic evidence?

Answer 4

pubmed clinical queries and change category to prognosis

Question 5

5 year survival means?

Answer 5

% patients surviving 5 years from some point in the course of their disease

Question 6

case fatality means?

Answer 6

% patients with disease who die of it

Question 7

disease - specific mortality means?

Answer 7

number of patients per 10,000 or 100,000 population dying of disease

Question 8

response means?

Answer 8

% patients showing some evidence of improvement following an intervention

Question 9

remission means?

Answer 9

% patients entering. phase in which disease is no longer detectable

Question 10

recurrence means?

Answer 10

% patients who have return of disease after a disease-free interval

Question 11

whats wrong with retrospective cohort studies? 2

Answer 11

1. recruitment bias
2. systematically miss patients with particular characteristics

Question 12

appraisal- how can you tell there is a representative and well defined sample of participants?

Answer 12

similarity at the start and all patients or consecutive cases/patients

Question 13

appraisal- were participants recruited at a common point in the disease/condition?

Answer 13

inception cohort is the best way to avoid this bias

Question 14

appraisal- was exposure determined accurately (intervention)

Answer 14

look at eligibility criteria and if participants were enrolled into the study but did not undergo completely

Question 15

appraisal- was follow up sufficiently long and complete?

Answer 15

loss to follow up (5 and 20 rule)
- <5% loss to follow up unlikely to influence results
>20 seriously impacts validity

Question 16

what is usually used to present prognostic data?

Answer 16

survival curves- showing the likelihood of an event changes over time

Question 17

how to interpret a survival analysis curve graph

Answer 17

curve can be smooth or square in nature
square means theres less subjects and a drop means 1 person has experienced the outcome

dotted black line shows us the average for 50% of patients

confidence intervals get wider as the number drops lower

Question 18

evidence to inform practice for prognostic questions 4

Answer 18

-share decision making
-likely clinical course allows for more informed decision making
-able to more effectively discuss options for patients
-must ensure patient understands what you’re saying

Question 19

what is the reporting standard for observational studies?

Answer 19

STROBE statment

Question 20

do cohort prognostic studies show prognostic factors that cause of an outcome

Answer 20

no, only establishes prognostic factor is associated with given outcome

Question 21

how is continuous and dichotomous data reported?

Answer 21

Continuous outcomes measures are usually reported as a mean value at a certain time period. For example, men with aphasia after their first stroke showed an average improvement of 12.3 on the Aphasia Quotient 1 year after stroke.

Dichotomous and ordinal outcomes are usually reported as the proportion of patients who experienced the outcome (that is, the risk of the event) at a particular point in time. For example, among adults over 65 years who present to primary care with back pain, 60% reported persistent disability (Roland-Morris Disability Questionnaire score of ≥4) at 6 months.

Question 22

what do survival curves show

Answer 22

Survival curves are often used to present prognostic data, and they show how the likelihood of an event changes over time

Question 23

2 main questions for appraising results?

Answer 23

The two main questions that you need to ask when considering the results of a prognostic study are: (1) how likely are the outcomes over time?; and (2) how precise are the estimates of likelihood?