Biostats/Other Flashcards
When to use a chi-square test for measuring statistical associations? What about z-tests, t-tests and ANOVA?
Categorical data = chi-square
2 means = t and z tests
3+ means = ANOVA
What does a hazard ratio represent?
Event rate in treatment group compared to comparison group
Cluster analysis
Study randomization occurs at the group level, not the individual level
False positive ratio
1 - specificity
False negative ratio
1 - sensitivity
Study population alters behavior because they know they are being observed
Hawthorne effect
What does power represent?
The ability of a study to identify a statistically significant difference between 2 groups
Number needed to treat
Absolute risk reduction = incidence in comparison group - incidence in treatment group.
NNT = 1/ARR
Susceptibility bias
A form of selection bias where a treatment regimen depends on the severity of their disease and is not randomized
Method of characterizing exposure-disease association in case-control trials
Odds ratio = ad/bc
Prevalence
Incidence x time
Attributable risk percent
(Risk in exposed - risk in unexposed)/risk in exposed
Also = (RR-1)/RR
How can you control for confounding?
Matching, restriction and randomization during the study design stage.
Stratification and statistical modeling during the analysis stage.
Requirement for a patient to enter hospice care
Prognosis ≤ 6 months
When can you accept nonmonetary gifts from interested third parties?
Direct benefit to patient care and of small value
How is benzo intoxication differentiated from opioid intoxication?
No pupillary changes or respiratory depression
When does shivering decrease in patients with progressive hypothermia? How does treatment vary from stage to stage?
Transition from mild (90-95F or 32-35C) to moderate (82-90F or 28-32C) hypothermia.
Mild = passive external rewarming
Moderate = active external rewarming
Severe = active internal rewarming
Treatment for ethylene glycol intoxication
Fomepizole or ethanol to competitively inhibit alcohol dehydrogenase, preventing formation of toxic oxalic acid and glycolic acid.
Antidote for cyanide poisoning
Hydroxocobalamin > sodium thiosulfate. If there is no antidote available give nitrites to induce methemoglobinemia.
When do you administer sodium bicarb to a patient who overdosed on TCAs?
Hypotension, QT prolongation or ventricular arrhythmia.
Antidote for organophosphate poisoning?
Atropine and pralidoxime are anticholinergics that will decrease parasympathetic stimulation from excess ACh due to organophosphate inhibition of AChE.
Neuroleptic malignant syndrome tetrad
Autonomic dysfunction, rigidity, fever and mental status changes
Type B adverse drug reaction
Dose independent. Type A is dose dependent.
Drugs used to reverse neuroleptic malignant syndrome
1) Dantrolene (muscle relaxant). Then bromocriptine and amantadine can be used.
Why should patients taking antipsychotics avoid being out in the cold?
Antipsychotics, especially 1st generation (fluphenazine) can inhibit the shivering mechanism and cause hypothermia.
What is the threshold for giving activated charcoal to a patient who overdosed on TCAs?
≤ 2 hours
Why do TCAs cause arrhythmias?
They inhibit fast Na channels in the His-Purkinje system
Management of patient with caustic ingestion?
Remove clothes, serial KUB/CXR to r/o perforation +/- gastrograffin in perf is suspected. If no perf, endoscopy within 24 hours.
Treatment of salicylate toxicity
Alkalinize urine with HCO3
Treatment of anticholinergic toxicity?
Physostigmine (AChE inhibitor)
Treatment of beta-blocker toxicity?
Glucagon
