This report shows patient adherence since initiating a medicine (i.e. how often a patient is getting their medicine dispensed and how many days their dispensed medicine can cover) and allows you to see and compare patients’ adherence patterns to different drugs for a specified period.
It can help you identify patient and provider characteristics and behaviour that may influence adherence that can inform or guide development of patient interventions or brand strategy.
How can this report be used?
The Adherence report could be used to:
- Provide an overview of patient adherence patterns to your brand
- Compare patient adherence across a brand or class of drug
- Investigate whether patient adherence is aligned with recommended dosing
- Determine whether adherence patterns differ based on drug, prescriber or patient-related factors
- Identify patterns and drivers of adherence for your brand and others to guide targeted marketing and brand strategy to improve patient outcomes
How is this report calculated?
Prospection uses the Proportion of Days Covered (PDC) method to calculate medication adherence. It can be interpreted as the proportion of days in the measurement period “covered” by prescription claims for the drug of interest. PDC is calculated per measurement period since a patient initiated the medicine.
Measurement period
The measurement period represents different time periods from when a patient initiated a medicine. You can select the length of the measurement period using the measurement period length filter. If the measurement period length selected is 3 months, the measurement periods displayed in the chart will be ‘month 1-3’, ‘month 4-6’, ‘month 7-9’ etc. from initiation.
A measurement period ensures the patient cohort is at the same distance from initiating the medicine, and assumes they are supposed to take the medicine for the entire period. When selecting the value, it is recommended to select a length longer than the expected or common resupply frequency.
Note: Only patients with sufficient data are included when measuring adherence (i.e. they have refilled their script at least once in total measurement periods, and are not deceased or stop data collection in each measurement period).
Proportion of days covered (PDC) estimates medication adherence by looking at the proportion (or percentage) of days in which a patient has access to the medication, over a defined measurement period. It is based on the script dispensing data and days' supply for each dispensing (how long the medicine should last before resupply is expected).
For example, using a measurement period of three months, in "month 1-3", patients are expected to use the medicine for the entire three months (90 days). Assume a patient had three scripts within this period and each script has a 30 day supply, but the patient was 10 days late when refilling the second script (after the previous supply had run out) and 5 days late when refilling the third script. This patient's medicine covers 75 days (15 days are uncovered) in "month 1-3", and adherence (PDC) will be 83.3% (75/90 x 100% = 83.3%).
Note:
- If a patient refilled their script before the end of the expected supply date, the start date of the next script is adjusted to the end of the previous script's supply (e.g. a patient refills their script on day 25 of a 30 day supply, the start date of that script is adjusted to day 31).
- The PDC method assumes patient's take the medicine as prescribed.
Adherence threshold
Typically, a patient is considered as adherent if the PDC is greater than 80% for an individual.
Within the report filters you can select an Adherence Threshold value to define and classify the level of adherence and non-adherence (e.g. if the threshold selected is 0.8, adherence is defined as ≥80% of days covered in the measurement period).
What does this report show you?
You can identify patient’s level of adherence (for a specified measurement period):
- on your drug
- on a competitor drug
- on a particular class of drug
- on a particular line of treatment
- for a particular demographic – sex, age, location
- for a particular procedure
- for a particular diagnoses
How can you modify the chart?
The filters allow you to explore the data by patient demographics at initiation, measurement period, initiation range and adherence threshold.
Display options
You can change the view of data by selecting an alternate option from the ‘Display Data As’ drop-down list.
Average PDC: The average level of adherence for the patient cohort (based on the defined adherence threshold) at different times since initiation.
For example, following up patients for the entire 3 months, the average level of adherence was 87.9%
Number of patients: The number of adherent and non-adherent patients (based on the defined adherence threshold) at different times since initiation.
- Adherent: Number of patients with PDC ≥ adherence threshold
- Non-adherent: Number of patients with PDC < adherence threshold
For example, following up patients for the entire three months, 36,310 patients were adherent, and 10,640 patients were non-adherent.
% of patients: The percentage of adherent and non-adherent patients (based on the defined adherence threshold).
- Adherent: % of patients with PDC ≥ adherence threshold
- Non-adherent: % of patients with PDC < adherence threshold
For example, following up patients for the entire three months, 77.3% patients were adherent, and 22.7% of patients were non-adherent.
