About the DrugStats Database
Drug Usage Statistics for the United States (2008 to 2018)
What is the ClinCalc DrugStats Database?
The ClinCalc DrugStats database provides free access to prescription drug utilization data estimates for patients in the United States. By leveraging this data, basic metrics about prescription drug usage can be estimated, including:
- Frequency of prescription fills for a medication
- Average out-of-pocket costs for a medication
- Comparative utilization data between similar medications
Where does the DrugStats Data Come From?
All medication utilization data comes from the annual Medical Expenditure Panel Survey (MEPS), a survey conducted by the Agency for Healthcare Research and Quality (AHRQ) via the United States government. This data is publicly available on the MEPS website for free.
In order for the ClinCalc DrugStats database to implement the MEPS data, basic data sanitization and standardization measures are required:
- Sanitization measures include identifying prescriptions that are not valid medications or those with incomplete data. As an example, there are entries within MEPS that do not include an actual medication name or only describe the medication class. Because these entries cannot be used to aggregate prescription utilization data, these entries are removed.
- Standardization measures are used to aggregate like medications so that they are "counted" as the same active ingredient. For example, "Vicodin", "hydrocodone/APAP", "hydrocodone/acetaminophen", and "APAP/hydrocodone" are all the same active ingredients but are treated as distinct entities in the MEPS database.
Using the FDA National Drug Code (NDC), the FDA Orange Book, and the NLM RxNorm databases, all ClinCalc DrugStats entries must be standardized against known chemical entities. This process of sanitization and standardization results in a slight reduction of prescription data (less than 3%) but dramatically improves the accuracy and reliability of the resulting data set.
How Frequently is the DrugStats Database Updated?
The MEPS prescribed medicines file is released every year in August; however, the survey data represents prescription fills from two years prior. As an example, the MEPS 2014 database was released in August 2016.
How Many Prescriptions Does the ClinCalc DrugStats Database Include?
The DrugStats Database coverage is comparable to the IMS Health database (now called QuintilesIMS), which costs tens of thousands of dollars. Using the 2014 year as an example, the MEPS survey data can be statistically extrapolated to include:
- About 3,000,000,000 total prescriptions
- About 500 unique active ingredients
Total Prescriptions in DrugStats Database by Year
Although it is possible to compare drug utilization per year, the MEPS database has made changes over time in how drug names are collected and reported. Most notably, starting in 2013, drug products were described as both a non-standard pharmacy product name and a standardized Multum Lexicon drug name. This change improves the yield of the sanitation and standardization process, but may slightly inflate the frequency of certain medications when comparing utilization between pre-2013 and 2013-onward.
Medications Poorly Represented in DrugStats
Because of the way that medications are recorded within the MEPS database, some medications are underrepresented primarily due to the fact that they are usually not prescription medications. These underrepresented drugs include:
- Herbal products and other complementary alternative medicines (CAM)
- Many over-the-counter products not adjudicated by a third party insurance
Prescription Coverage by the Top 200 and Top 300 Drugs
Particularly in colleges of pharmacy, it is common for students to learn the "top 200 drugs" or "top 300 drugs" in order to focus on the most commonly seen medications. This practice takes advantage of the fact that the vast majority of outpatient prescriptions filled in the United States comes primarily from a minority of the most common medications: