Population Health Analytics

Prescription patterns are one of the most clinically rich — and often underutilized — signals in population health analytics.

Pharmacy spending has also become an increasingly significant share of health care costs. Prescription drug spending reached $467 billion in 2024, growing 7.9% year over year¹ and continuing to outpace overall medical cost trend.² Among large employers in the U.S., pharmacy spending now accounts for 27% of total health care costs, up from 21% in 2021, according to the Business Group on Health.³

But beyond financial impact, pharmacy data can reveal things diagnosis data alone often cannot. Medication patterns may indicate conditions being treated before a formal diagnosis is documented, highlight gaps between prescribed treatment and actual adherence, and surface treatment burden such as polypharmacy and medication complexity. Plus, for some hard-to-reach or intermittently engaged populations, pharmacy activity may also represent the only consistent longitudinal health care signal available.

Unlike many other forms of health care data, pharmacy data reflects the part of care patients manage themselves: whether medications are filled, taken consistently, adjusted over time or eventually discontinued. It offers insight not only into clinical treatment decisions, but also into patient behavior and emerging risk.

What Medication Data Reveals Beyond Diagnosis

Medication data can provide meaningful insight into patient health even when diagnosis coding is incomplete or unavailable. Within the ACG System, Rx-Morbidity Groups (RxMGs) use prescription drug patterns to help describe a population’s condition burden and clinical complexity.

Pharmacy markers can also help identify gaps in care. Across 17 chronic conditions, the ACG System can identify diagnosed conditions with no corresponding treatment, as well as prescribing patterns that may suggest an undiagnosed condition requiring further evaluation. These signals help organizations identify opportunities for proactive intervention earlier in the care journey.

Looking Beyond the Prescription

Pharmacy data provides visibility into far more than what medications were prescribed. It can help organizations identify rising clinical risk before avoidable utilization occurs.

• Medication Adherence The World Health Organization estimates adherence to chronic disease therapies averages only 50% in developed countries, and even lower in developing countries.⁴ ACG System measures such as Medication Possession Ratio (MPR), Proportion of Days Covered (PDC) and refill gap analysis help identify patients at risk of nonadherence. A gap in a diabetes or cardiac medication refill, for example, can serve as an early care management trigger before complications occur.

• Polypharmacy and Medication Complexity As medication burden increases, so do risks of nonadherence, drug interactions, patient burden and rising costs. The ACG System uses active ingredient count as a more precise measure of medication burden than prescription count alone. The Medication Complexity Score (MCS) further evaluates regimen complexity and high-risk medications to help identify patients who may benefit from intervention.

• Opioid Utilization Patterns Pharmacy data can also highlight prescribing patterns associated with elevated risk, including chronic opioid use, concurrent opioid and benzodiazepine use, and indicators of opioid dependency. Because opioid dependency is often underdiagnosed or underreported, prescribing-based signals can support identification.

Supporting a More Complete View of Patient Risk

Within the ACG System, pharmacy data can be analyzed alongside segmentation, utilization patterns and social needs indicators to support a complete, whole-person understanding of patient risk.

This integrated view helps organizations move beyond identifying conditions alone to understanding how patients are managing their health, where gaps may exist, and where intervention is most likely to improve outcomes.

Moving Pharmacy Data from Supplemental to Strategic

Pharmacy data is often treated as supplemental, but it can also serve as a primary data feed into the ACG System. Whether used independently or combined with medical and social data, pharmacy insights provide a powerful lens into patient behavior, clinical complexity and opportunities for earlier intervention.

To learn more about how the ACG System can support your organization, visit hopkinsacg.org or contact us at acginfo@jh.edu. If you are a current ACG System customer, please reach out to your Account Manager.

References

1. Centers for Medicare & Medicaid Services. National Health Expenditure Data, 2024.
2. PwC Health Research Institute. Behind the Numbers 2026: Medical Cost Trend.
3. Business Group on Health. 2025 Large Employer Health Care Strategy Survey.
4. WHO. Adherence to Long-Term Therapies: Evidence for Action.