Outcome measures and drug use measures.

1. OUTCOME
MEASURES & DRUG
USE MEASURE
BY: ASIYA NAAZ
PHARM.D 5TH YEAR

2. INTRODUCTION
 Epidemiology is about identifying association between exposure
and outcomes.
 To identify any associations, exposure and outcomes must first be
measured in quantitative manner.
 In treatments & healthcare programs, outcomes are the results of
treatment or care, which includes both positive and negative
results.
 Outcome measurement: It is defined as the systematic
quantitative analysis of the outcome indicator at a point of time.
 Outcome indicator: measures performance of function process
and outcomes over a period of time.

3. 2 APPROACHES
 These measures are used to find out whether the goal of the
patient, are identified and achieved. Measurement of outcome
can be done by two approaches:
1. STATISTICAL METHOD
PREVALENCE INCIDENCE
CUMULATIVE
INCIDENCE
INCIDENCE RATE/
INCIDENCE DENSITY

4. PREVALANCE
 It is the proportion of people affected with a disease or exposure
to a particular drug in a population at a “specific point or period of
time”.
 Usually determined by surveying the population of interest.
 Prevalence varies between 0-1; can be expressed as percentage.
 It is a census type of measure, indicating how frequently a disease
is at a period of time.
 Estimate the magnitude of health.
 To identify the potential high risk population community.
 Mathematically, Prevalence=A/B
 A= no. of population with disease at given time.
 B=Total no. of population at a given time.
 Ex. If there are 1000 pts with epilepsy in a district of 10,00,000
population.Then prevalence of epilepsy= 1000/10,00,000=0.001%

5. INCIDENCE
 Definition: It is a measure of risk of developing some “new
condition” within a specific period of time.
 In the case of descriptive studies 2 measurements of incidents are
commonly use:
 1. Cumulative incidence
 It is a no. of new cases within a specific period of time, divided by
the size of population initially at risk.
 It is used for the measure of the risk of disease or probably
probability of developing the disease during specified period.
 Normally it is measured with an inception cohort i.e. a large group
of population is observed over a period of time, and the no.of
cases or outcomes is measured.

6. INCIDENCE RATE
 C.I = No.of new cases of disease or injury during specified period
size of population at start of period
Ex: If a population initially contains 1000 non disease persons & 28
develop a condition over two years of observation, the incidence
proportion is 28 cases per 1000 persons.
Incidence rate: It is a no.of new cases per population at risk in a
given period of time.
 Describes the probability of a new case occurring during a given
time interval or how quickly disease occurs in a population.
 Measurement combining the no.of persons and their time
contribution (years, months or weekly) in a study.
 IR= no.of new cases of disease or injury during specified period
 total time each person was observed (totaled for all persons)

7. 2. DRUGUSE
MEASURES
RELATIONSHIP BETWEEN PREVALENCE & INCIDENCE
 P = I X D; D = duration
 It shows, longer the duration of the disease, greater the
prevalence.
DRUG USE MEASURES
1. MONETARY UNITS
2. NUMBER OF PRESCRIPTIONS
3. UNITS OF DRUGS DISPENSED
4. DEFINED DAILY DOSES (DDD)
5. PRESCRIBE DAILY DOSE (PDD)
6. MEDICAL ADHERENCE MEASUREMENT

8. 1. MONETARY
UNITS
2. NO.OF
PRESCRIPTION
1. Drug use has been measured in monetary units to quantify the
amounts being consumed by population.
 It can indicate the burden on society from drug use.
 Monetary units are convenient and can be converted to a common
unit, which then allows for comparison.
 The disadvantage is quantifies of drug actually consumed, are not
known and prices may vary widely.
2. It has been used in research, due to the availability and ease.
 Prescription number analysis is used to get rough estimates like
percentage of analgesic drugs, oral contraceptives or antibiotics
used by population.

9. 3. UNITSOF DRUG
DISPENSED
 Units of drugs represent measures like no. of capsules or tablets or
doses of vaccines.
 It is easy to obtain and can be used to compare usage trends
within population.
 Helps to analyze drug use trend in various countries.
 Helps to compare hypothesis generated related to drug use, like
overuse or under use.
 It has limilations like units of drugs dispensed need not always
reflect the actual number of drugs used by the population.
 Hence, difficult to determine the actual no. of pts exposed to the
drug.

10. 4. DEFINED DAILY
DOSES (DDD)
 According toWHO, the DDD is assumed avg maintenance dose
per day for a drug for its main indications in adults.
 Normally expressed as DDD/1000 pts/day or DDD/100 bed/day.
 Drug usage = item used amount of drug per item
DDD
Ex:A pt has taken paracetamol as painkiller. It is having DDD= 3g i.e.
avg pt who uses paracetamol uses 3g in a day or within period of
24hrs.
This is equivalent tp 6 standard tablets of 500mg each. If pt
consumes 24 such tablets.
DDD = 24 X 500 / 3
DDD = 4

11. 5. PRESCRIBE
DAILY DOSE (PDD)
6. MEDICAL
ADHERENCE
MEASUREMENTS
5. It is the avg daily dose of a drug that has actually been prescribed.
 Calculated from representative samples of prescription.
 PDD is useful for validating that DDD.
6. Consist of :
 Biological assays
 Pill counts
 Weight of topical medications
 Electronic monitoring
 Patient interviews

12. 1. Biological assays
2. Pill counts
 1. biological assays measure the conc.Of a drug, its metabolites,
or tracer compounds in blood or urine of a patient.
 Drug or food interaction, physiological differences, dosing
schedules and the half life of the drugs may influence the results.
 All these methods have high costs for assays that limit the
feasibility of these techniques.
 2. counting the no. of pills remaining in a pts supply and
calculating the no. of pills that the pt has taken since filling the
prescription is easiest method for calculating patient medication
adherence.
 Patterns of non-adherence are often difficult to discern with a
simple count of pills on certain date weeks to months afer
prescription was filled.

13. 3.Weight of topical
medications
4. Electronic
monitoring
 3. the weight of a topical medication remaining in a tube is used
as a measure of adherence.
 When compared with patient log books of daily medication use,
weight estimates of adherence were considerably lower than
patient log estimates.
 4. the medication event monitoring system MEMS manufactured
by Aardex Corporation allows the assessment of the number of
pills missed during a period as well as adherence to dosing
schedule.
 The system electronically monitors when the pill bottle is opened,
and the researcher can download the information to a computer.
 The availability and cost of this system could limit the feasibility of
its use.

14. 5. Patient
interviews
5. Interviewing the patients to assess their knowledge of the
medication they have been prescribed and the dosing schedule
provide information as to whether the patient is adherent with the
actual dosing schedule.

15. THANK
YOU