Quiz 5 Flashcards
Pharmacoepidemiology
study of the use, risks, and benefits of drugs in POPULATIONS
Pharmacovigilance
continual monitoring for unwanted effects and other safety-related aspects of marketed drugs
Comparative Effectiveness Research (CER)
determining what therapeutic intervention works best for a given disorder in patients likely to be seen in clinical practice
Pragmatic Research
studies (using randomization) that often test small practical changes that could have an impact on health outcomes
Experimental vs Nonexperimental (Observational)
Experimental: look at cause & effect by controlling interventions
- RCT’s
Nonexperiemental: cannot control exposures –> simply gathering groups that have been exposed
- case control
- cohort
- pharmacoepidemiologic & pharmacovigilance
Applications of Pharmacoepidemiology
- supplement information from premarketing studies
- better quantify adverse reactions and beneficial effects
- higher precision compared to a RCT as a RCT has such a low sample size that it is hard to detect small, rare instances
- includes populations not included in premarketing trials
- study effects of other drugs/diseases and other drugs for same indication - identify new information not available from premarketing studies
- previously undetected adverse reactions & benefits (rare adverse effects and delayed effects)
- patters of drug utilization
- varied doses
- economic impact of drug use
ULTIMATELY PHARMACOEPIDEMIOLOGY STUDIES CAN ANSWER QUESTIONS NOT ASSESSED IN RCT OR ANSWER NEW QUESTIONS
Data Sources for Pharmacoepidemiology
Adverse Drug Reaction Reports
- limitation: self reported and self selected
Medical Claims Data
- private & governmental medical and prescription insurance providers
- some are collected and sold by third party vendors (TRUVEN)
- contains diagnostic codes, procedure, labs, prescription codes, etc
- limitation: only used for billing purposes with no specific notes and not performed by a clinician necessarily
Electronic Medical Records (EMR)
- instiutional or health system
- Advantage: much more granular
- Limitation: difficult to access
Bias
systematic deviation from the truth that distorts the results of research
Confounding Variable
- relationship between the exposure and response is actually attributable to another variable
- confounder is independent of both the exposure and outcome
Information Bias
- bias related to information regarding the exposure or outcome
- includes measurement or classification error and patient reporting recall
Ex) Hawthorne
- changed the lighting in the building to see if it effected productivity
- it did increase productivity but it was because the workers knew someone was watching them
Detection Bias
- specific outcome is diagnosed preferentially in subjects exposed to the agent
- more likely to look for an side effect in someone exposed to the drug
Ex) Amiodarone vs Beta Blockers for Pulmonary Toxicities
- amiodarone is known to cause pulmonary toxicity so we are more likely to look for that side effect
- BB are not associated with
Confounding by Indication
- indication for a drug or severity of the disease predicts the use of the drug
- appears when the reason of prescription is associated with the outcome of interest
Ex) COXIB’s and GI bleeds
Ex) ACE-I in preventing MI in patients with HTN
Selection Bias
- bias related to procedures used to select patients
- due to systematic differences in characteristics between those who are selected for the study and those who are not
Ex) normal patients from a hospital vs patients for the cancer center
Referral Bias
- reason for the encounter is related to the drug treatment
Ex) the use of the drug contributes to the diagnostic process
Protopathic Bias
- exposure of interest is used unknowingly to treat an adverse event related to outcome/agent is used for early manifestation of a disease that has not been diagnosed
Ex) antipsychotic may be started to treat delirium, but the drug may have anticholinergic effects that contribute to delirium
