This document discusses various measures used to quantify drug use and outcomes in pharmacoepidemiological studies. It describes prevalence as the proportion of people with a disease or exposed to a drug at a given time. Incidence is the number of new cases within a time period, while incidence rate is the number of new cases per unit of person-time at risk. Drug use is commonly measured by the number of prescriptions, units of drug dispensed, defined daily doses which estimates average maintenance dose, and prescribed daily doses which is the average dose actually prescribed. Adherence is often measured through biological assays, pill counts, pharmacy records, and patient interviews.

1. OUTCOME MEASURE AND DRUGUSE MEASURES
ADHIN ANTONY XAVIER
Assistant Professor
CES college., KURNOOL
Andhra Pradesh

2. OUTCOME MEASUREMENT
The occurrence of pharmacoepidemiological outcomes is
commonly expressed by measurements such as,
• Prevalence
• Cumulative incidence and
• Incidence rate

3. PREVALENCE
 It is concerned with the disease status
 It is the proportion of people affected with a disease or exposed
to a particular drug in a population at a given time
 It is usuallydetermined bysurveying the population of interest
 Prevalence varies between 0-1, it can also be expressed as a
percentage

4. Prevalence = A/B
A- number of population with disease at a given time
B- total number of population at a given time

5. • It is a measure of the risk of developing some new
condition with in a specified period of time
• It is better expressed asa proportion or as a rate
INCIDENCE:

6. INCIDENCERATE:
• It is the number of new cases per unit of person-time at risk.
• It describes the probability of a new case occurring during a given
time interval

7. CUMMULATIVE INCIDENCE(INCIDENCE PROPORTION)
• It is the number of new cases with in a specified time period divided by
the size of the population initiallyat risk

8.  Monetary units
 Numbers of prescription
 Units of drug dispensed
 Defined daily doses
 Prescribed daily doses
 Medication adherence measurement
DRUGUSE MEASURES:

9. MONETARY UNITS
• Drug usehas beenmeasuredin monetary units to quantify the amounts being
consumed by population
• It canindicate the burden ona society from drug use
• Monetary units are convenient & can beconverted to a commonunit, which
then allows for comparison
DISADVANTAGE:
quantities of drugs actually consumed are not known & prices may vary widely

10. • It has been used in research due to the availability & ease
DISADVANTAGE :
• quantities dispensed vary greatly as duration of treatment
NUMBER OF PRESCRIPTIONS

11. • Units of drug dispensed like tablets, vials is easy to obtain & can
beused to compareusage trends within population
DISADVANTAGE:
• No information is available on the quantities actually taken by the patient
• Determine the actual no. Ofpatients exposed to the drug
UNITS OF DRUG DISPENSED :

12. It is the estimated avg.Maintenance dose perday of a drug whenused in its
major indication
It is normally expressed as DDD/1000 patients/ / day
It is helpful in describing & comparing patterns of DU & provides denominator
data for estimation of ADR rates
It allows comparisons between drugs in the same therapeutic class
• DISADVANTAGE:
• problems arises when doses vary widely like with antibiotics orif the drug
has more than 1 major indication
DEFINED DAILY DOSES

13. PRESCRIBED DAILY DOSES
• It is the averagedaily dose of a drug that has actually been prescribed
• Calculated from representative sample of prescriptions
DISADVANTAGE:
it does notindicate number Of population exposedto drug

14. MEDICATION ADHERENCE MEASUREMENTS
• Biological Assays
• Pill Counts
• Weight of Topical Medications
• Electronic Monitoring
• Pharmacy Records and Prescription
Claims
• Patient Interviews
• Patient Estimates of Adherence