Study Designs

2 types of study designs

experimental

observational

experimental designs

RCT and non-randomised

Quasi-experimental

observational designs

case-control

cross-sectional

cohort

ecologic

case study / case report

RCT - stats - measures of association

relative risk

hazard ratio

correlation coefficients

chi-squared tests

risk difference

relative risk reduction

number needed to treat

quasi experimental- stats - measures of association

relative risk

hazard ratio

correlation coefficients

chi-squared tests

risk difference

relative risk reduction

number needed to treat

cohort - stats- measures of association

relative risk

hazard ratio

correlation coefficients

chi-squared tests

risk difference

relative risk reduction

number needed to treat

case control - stats - measures of association

odds ratio

correlation coefficients

chi-squared tests

cross sectional - stats- measures of association

odds ratio

prevalence ratio (analogous to relative risk)

correlation coefficients

chi-squared tests

ecologic - stats - measures of association

rate comparisons

correlation coefficients

experimental studies

one or more factors altered and effects examined

can be uncontrolled (trials without a control group for comparison) or controlled (trials with a control group for comparison)

controlled trials

RCT

and NON-RCT

RCT

subjects allocated randomly to intervention or control group

non-RCT

subjects allocated to intervention or control group without randomisation method

analytic studies

examine etiology and causal associations

observational studies

observations made without any interventions

observational studies - outcome determination

after exposure (prospective)

at the same time as exposure (cross-sectional)

before the exposure (retrospective / case control)

exposure

the thing that differs between the groups

IE. BMI, smoking hx, weight, strength, treatment, gene, training volume, image findings

literature reviews

summarize/synthesize existing research

literature review examples

critical review

narrative review

scoping review

systematic review

qualitative systematic review

mixed methods review

umbrella review

meta-analysis

narrative lit review

subjective inclusion of studies

no detailed methodology

limited search

unreproducible

systematic review

studies included based on specific question / inclusion / exclusion criteria (pre-specified)

structured process / protocol

systematic and exhaustive search process - collate all empirical evidence

transparent, explicit, systematic methods

minimizing bias

levels of evidence

systematic review

RCT

NON-RCT

pre-post design . case series, case reports

theoretical models / expert opinion

scoping review

examine a broader area to identify gaps in knowledge

clarify concepts

reports on types of evidence avaliable

map a body of literature

report on types of methodologies avaliable