Measuring Your Medication Adherence: A Practical Checklist

By Joe Barnett On 11 Mar, 2026 Comments (9)

Have you ever filled a prescription, only to realize weeks later that you haven’t taken the pills like you were supposed to? You’re not alone. More than half of people with chronic conditions like high blood pressure, diabetes, or cholesterol don’t take their meds as prescribed. And it’s not because they’re forgetful or careless - often, it’s because the system doesn’t help them track what’s really happening. The good news? You can measure your own adherence, and it doesn’t require fancy tech or a clinic visit. This checklist gives you a clear, practical way to know where you stand - and what to do next.

Why Tracking Medication Adherence Matters

Taking your medicine exactly as your doctor ordered isn’t optional. It’s the difference between controlling your condition and ending up in the hospital. For example, if you have hypertension and skip your blood pressure pills even a few times a week, your risk of stroke goes up by nearly 40%. Same with diabetes - missing doses can spike your HbA1c levels, leading to nerve damage, kidney problems, or vision loss over time.

The problem? Most people think they’re doing fine. Studies show that when patients are asked if they take their meds, 80% say yes. But when you actually watch them - through electronic caps that record when bottles are opened - only about 50% are truly on track. That gap is why measurement matters. You can’t fix what you don’t measure.

Step 1: Use a Pill Count

This is the simplest, oldest, and still surprisingly useful method. Every week, take out your pill bottle and count the remaining pills. Then compare that number to how many you should have left based on your prescription.

For example: You were prescribed 30 pills to last 30 days. After 14 days, you should have 16 left (30 minus 14). If you have 22, you’ve missed 6 doses. That’s a 20% drop in adherence in just two weeks.

Do this once a week. Keep a small notebook or use your phone’s notes app. Write down the date and the count. After a month, add up the missed doses. If you missed more than 4 days out of 30, you’re below the 80% adherence threshold that doctors use to judge if treatment is working. This isn’t about guilt - it’s about data.

Step 2: Track Your Prescription Refills

Most pharmacies track when you refill your meds. Log into your pharmacy’s app or call them. Ask for your Proportion of Days Covered (PDC) a metric that calculates the percentage of days in a given period where you had the medication available, based on refill records. This is the gold standard for chronic conditions like diabetes or heart disease.

Here’s how PDC works: If you have a 30-day supply and refill on time every month, your PDC is 100%. If you wait two weeks to refill, you have a gap. PDC counts only the days you actually had the drug on hand. A score below 80% means you’re at risk. Most health plans now use this number to decide if your treatment is effective.

Don’t assume your doctor knows this number. Ask for it. If you use multiple pharmacies, your PDC may be wrong - because refills from other stores won’t show up. That’s why combining this with a pill count gives you the full picture.

Step 3: Take the MARS-5 Questionnaire

The Medication Adherence Report Scale (MARS-5) a validated 5-item questionnaire that asks patients to rate how often they miss doses or change their regimen was developed by researchers at University College London and is used in clinics worldwide. It takes 90 seconds. Here’s how it works:

Answer these five questions on a scale of 1 to 5:

How often do you miss a dose?
How often do you take less than the prescribed amount?
How often do you take more than prescribed?
How often do you stop taking the medicine without telling your doctor?
How often do you forget to take your medicine?

Score each from 1 (very often) to 5 (never). Add them up. A total score of 20 or higher means you’re adherent. Below 18? You’re at risk. This isn’t perfect - people often overreport. But it’s a great conversation starter with your doctor. Bring the score. Say: “I scored 16. I think I’m missing doses. Can we fix this?”

Person viewing pharmacy app showing low medication adherence score

Step 4: Look for Patterns in Your Life

Adherence isn’t just about pills. It’s about routines. Do you skip meds on weekends? Do you forget when you travel? Do you stop because of side effects you never told anyone about?

Keep a simple log for one week:

Did you take your pill at the same time every day?
Did you eat or drink anything that might interfere (like grapefruit juice with statins)?
Did you feel better after taking it? Worse?
Did you run out of pills before your refill?

Patterns matter more than single misses. If you always skip your morning pill on Mondays, maybe you’re rushing. If you stop after a side effect, you need to talk to your doctor - not quit cold turkey.

Step 5: Use Technology - But Don’t Rely on It Alone

Smart pill bottles, phone alarms, and apps can help. But they’re tools, not solutions. A 2023 study found that while 70% of people used reminders, only 30% actually improved adherence. Why? Because reminders don’t fix the reason you’re skipping pills.

If you use tech:

Choose one app - don’t juggle five.
Set alarms for the same time every day - not just “morning.”
Use a pill organizer with days of the week.
Turn off notifications if they annoy you. They won’t help if you ignore them.

The best tech is the one you actually use. If you hate alarms, use a sticky note on your toothbrush. If you forget your phone, keep a pill bottle next to your coffee maker.

What 80% Adherence Really Means

Doctors don’t expect perfection. But they do expect consistency. For chronic conditions, 80% adherence means:

Missing no more than 2-3 doses in a 30-day period.
Never letting your supply run out for more than 2-3 days.
Not skipping doses because you feel fine.

Why 80%? Because studies show that below that line, your body doesn’t get enough of the drug to work properly. For blood pressure meds, every 10% drop in adherence increases your risk of heart attack by 18%. For diabetes drugs, it raises your HbA1c by 0.4%. That might sound small - but it’s enough to push you from “controlled” to “at risk.”

Person holding medication questionnaire with ghostly missed doses floating around

What to Do If You’re Below 80%

Don’t panic. Don’t feel ashamed. Just act.

Call your pharmacist. Ask: “Can I switch to a once-daily version?” Many meds have long-acting forms.
Ask your doctor about pill packs. Some pharmacies offer blister packs with daily doses pre-sorted.
Request a 90-day supply. Fewer refills = fewer chances to forget.
Bring your pill count or MARS score to your next visit. Say: “I’m trying to improve. Can we adjust my plan?”

Most doctors want to help. But they can’t read your mind. You have to speak up.

Common Myths About Medication Adherence

Myth: “If I feel fine, I don’t need to take it.” Truth: Many chronic meds work best when you don’t feel symptoms. Stopping them can cause rebound effects.
Myth: “I’m not the only one skipping doses.” Truth: Yes, you’re not alone - but that doesn’t make it safe.
Myth: “My doctor knows I’m not taking it.” Truth: Unless you tell them, they assume you are.
Myth: “I’ll just take more next time to make up for it.” Truth: Doubling up can be dangerous. Never do it without asking your doctor.

Next Steps: Your 7-Day Adherence Plan

Start today. Here’s what to do in the next week:

Count your pills today. Write down the number.
Log into your pharmacy app. Check your PDC for the last 30 days.
Answer the MARS-5 questions. Add up your score.
Place your pill bottle next to something you use daily - toothbrush, coffee maker, phone charger.
Set one alarm for the same time every day.
Write down one reason you might skip your meds - and one way to fix it.
Call your pharmacy or doctor. Ask: “Can we make this easier?”

You don’t need to be perfect. You just need to be aware. And now, with this checklist, you are.

What is the most accurate way to measure medication adherence?

The most accurate method is electronic monitoring using devices like MEMS caps that record each time a bottle is opened. These give real-time, objective data. But they’re expensive and not practical for everyday use. For most people, combining pill counts with pharmacy refill records (PDC) and the MARS-5 questionnaire gives the best balance of accuracy and practicality.

Is it okay to skip a dose if I feel fine?

No. Many medications, especially for chronic conditions, work by maintaining steady levels in your body. Skipping doses - even if you feel fine - can cause those levels to drop, which may trigger symptoms later or make your condition worse over time. Always follow your prescribed schedule unless your doctor tells you otherwise.

Can I use my phone app to track my adherence?

Yes, but only if you use it consistently. Apps that send reminders are helpful, but they don’t prove you took the pill. Pair the app with a daily check: after the alarm goes off, open the app and tap “taken.” This creates a log you can review weekly. Avoid apps that just remind you - they’re useless if you ignore them.

Why does my doctor care about PDC?

PDC, or Proportion of Days Covered, is the standard metric used by health systems to judge if your treatment is working. If your PDC is below 80%, your condition is likely not under control, even if your lab results look okay. It also affects insurance coverage - some plans require a minimum PDC to approve continued prescriptions or offer financial incentives.

What if I can’t afford my medication?

Talk to your pharmacist or doctor immediately. Many drug manufacturers offer patient assistance programs. Pharmacies sometimes have discount cards. You can also ask about generic versions or lower-cost alternatives. Never skip doses because of cost - there are solutions, but you have to ask.

How often should I check my adherence?

Check weekly for the first month. After that, check every two weeks. If you’ve been consistent for 3 months, you can reduce to monthly. The goal is to catch slipping patterns early - before they become habits. If you’re changing meds, go back to weekly checks.