how to calculate NNT
100/absolute risk reduction
(so if reduction from 13 to 5%, then it is 100/8=12.5)
How to calculate sensitivity
TP / (TP + FN)
how to calculate specificity
TN / (TN + FP)
True negatives divided by the total number of people who are actually negative for the condition
Calculate Relative Risk reduction
RRR = (CER - EER) / CER
Control Event Rate = risk in placebo group
Experiential Event Rate = risk in treatment group
Absolute Risk Reduction = CER - EER
meta analysis vs systematic review
- MA: a statistical technique to combine quantitative data from multiple studies
- SR: reproducible search, appraisal, and synthesis of all relevant literature on a specific question
- MA needs a SR as its foundation
StudyPRN: When is an N of 1 Trial suitable?
To investigate the efficacy of an infrequently used medication, e.g. in the management of cancer pain
Measure problem before Tx (baseline) then measure again with Tx and again after terminated
Clinical governance components
- clinical effectiveness
- risk management
- patient and public involvement
- audit
- staff management
- education and training
- information management
Black Triangle ▼ drugs
- New medicine under intensive monitoring
- All suspected reactions (even minor) need to be Yellow Card reported
When to use Yellow Card
- fatal
- life-threatening
- hospitalising
- or any reaction to Black Triangle drug
as well as for new drugs, vaccines, and medical devices.
Standards assessment vs needs assessment in audits
- Needs assessment look at what gaps there are to inform future improvement/planning
- Standards assessment looks at existing practices compared to a standard
What does p=0.01 mean?
1% chance of occurring by chance
What does confidence interval mean?
- e.g. 95% confidence level means that if the study were repeated, 95% of calculated intervals would contain the true population parameter
- If CI goes over 0 then unlikely statistically signif
What is difference between reference range and confidence interval?
- RR refers to individuals = Individual Variation
- CI refers to estimates = Estimate Precision
Absolute risk reduction
New end point minus old
Different levels of evidence
- Ia Meta-anal ofRCT
- Ib ≥ 1 RCT
- IIa ≥ 1 controlled study without randomisation
- IIb ≥ 1 quasi-experimental study
- III non-experimental descriptive studies (comparative, orrelation, case-control studies)
- IV expert committee reports / opinions and/or linical experience
Case control VS cohort study
- Case con: Pt with disease are matched with people without disease then compare characteristic / factor across two groups (retro or prospective)
- Cohort studies enroll two groups based on common characteristic status and compare health outcome (i.e. disease)
what is best measure of drug absorption?
Bioavailability
area under the curve of plasma conc over time, comparing PO AUC to IV AUC
