General Health News · Supplementary · from General Health News
Case 3: Health Literacy and Medication Adherence
Patient Presentation
Demographics: 63-year-old male retired construction worker
Chief Complaint: "My sugar has been running high and I don't understand why — I've been taking my pills."
History of Present Illness: Mr. Williams was diagnosed with type 2 diabetes mellitus eight years ago and hypertension twelve years ago. He presents to the clinic after his home glucometer readings have consistently been between 250 and 350 mg/dL over the past three weeks. He states he has been "taking his pills" but upon detailed questioning, significant adherence issues emerge.
When asked to describe his medication regimen, Mr. Williams states he takes "the white pill in the morning and the other one at night." He is unable to name any of his medications, state their doses, or articulate their purposes. He recently received a 90-day mail-order refill and reveals that he has been taking metformin 500 mg once daily instead of the prescribed 1000 mg twice daily because "the bottle said 500 so I take one." He discontinued his glipizide two months ago because "it was making me dizzy" but did not inform his physician. He takes lisinopril intermittently, only when he "feels his pressure is up."
He completed education through 10th grade and reports difficulty reading medication labels and patient education materials. He does not use a smartphone and relies on his daughter to schedule appointments.
Past Medical History:
- Type 2 diabetes mellitus (8 years)
- Hypertension (12 years)
- Hyperlipidemia
- Diabetic peripheral neuropathy
- Osteoarthritis of bilateral knees
Medications (prescribed vs. actual):
- Metformin 1000 mg BID (taking 500 mg once daily)
- Glipizide 10 mg BID (discontinued 2 months ago)
- Lisinopril 20 mg daily (taking intermittently)
- Atorvastatin 40 mg daily (taking consistently)
- Gabapentin 300 mg TID (taking once daily at bedtime only)
Social History:
- Retired construction worker; limited pension income
- 10th grade education; limited health literacy
- Lives alone; daughter visits weekly
- Former smoker (30 pack-years, quit 5 years ago)
- No alcohol use
Family History:
- Mother: Diabetes, stroke
- Father: Unknown (estranged)
- Brother: Diabetes, below-knee amputation
Physical Examination
- Vital Signs: BP 158/94 mmHg, HR 88 bpm, RR 18, Temp 98.2°F, BMI 32.1 kg/m², fingerstick glucose 312 mg/dL
- General: Obese male, appears older than stated age
- HEENT: Cotton-wool spots on fundoscopic exam bilaterally; no rubeosis iridis
- Cardiovascular: Regular rate and rhythm; S4 gallop present
- Respiratory: Clear to auscultation
- Abdomen: Obese, non-tender
- Extremities: Decreased sensation to monofilament testing bilateral feet (4/10 sites); dry skin with fissuring bilateral heels; pulses diminished dorsalis pedis bilaterally
- Neurological: Decreased vibratory sensation bilateral great toes; absent ankle reflexes
Workup and Results
Laboratory Studies:
| Test | Result | Reference Range |
|---|---|---|
| HbA1c | 10.4% | < 7.0% (goal) |
| Fasting Glucose | 298 mg/dL | 70-99 mg/dL |
| Creatinine | 1.6 mg/dL | 0.7-1.3 mg/dL |
| eGFR | 48 mL/min/1.73m² | > 60 mL/min/1.73m² |
| BUN | 32 mg/dL | 7-20 mg/dL |
| Urine Albumin/Creatinine Ratio | 186 mg/g | < 30 mg/g |
| Potassium | 5.1 mEq/L | 3.5-5.0 mEq/L |
| Total Cholesterol | 198 mg/dL | < 200 mg/dL |
| LDL Cholesterol | 112 mg/dL | < 100 mg/dL |
| HbA1c (6 months ago) | 8.2% | < 7.0% |
Imaging/Additional Studies:
- Diabetic retinal screening: Mild non-proliferative diabetic retinopathy bilateral
- Monofilament exam: Loss of protective sensation bilateral feet
- Medication Possession Ratio (pharmacy data): 42% for metformin, 0% for glipizide, 58% for lisinopril
Clinical Image
Diagram illustrating how low health literacy contributes to medication non-adherence and poor clinical outcomes, with intervention strategies at each level. Source: Educational illustration.
Diagnosis
Uncontrolled Type 2 Diabetes Mellitus due to Medication Non-Adherence Secondary to Limited Health Literacy (ICD-10: E11.65, Z55.0)
Key Diagnostic Criteria:
- HbA1c rising from 8.2% to 10.4% over 6 months
- Medication Possession Ratio well below the 80% adherence threshold
- Unable to name medications, state doses, or describe indications
- Evidence of end-organ damage: nephropathy (eGFR 48, albuminuria), retinopathy, neuropathy
- Validated low health literacy on REALM assessment (4th grade reading level)
Treatment Plan
- Health Literacy Assessment: Administer REALM (Rapid Estimate of Adult Literacy in Medicine) — result: 4th grade reading level; all future communication to use teach-back method and plain language
- Medication Simplification: Transition to once-daily combination medications where possible; consider empagliflozin (renal and cardiovascular benefit given CKD stage 3b and albuminuria) replacing glipizide; continue metformin at reduced dose (500 mg BID given eGFR)
- Adherence Tools: Pill organizer with color-coded compartments; pictographic medication schedule (pictures instead of text); enlist daughter as health care proxy and medication manager
- Diabetes Education: Referral to certified diabetes care and education specialist (CDCES) for low-literacy tailored education; focus on survival skills first (hypoglycemia recognition, when to seek emergency care)
- Nephrology Referral: eGFR < 50 with significant albuminuria warrants nephrology co-management
- Ophthalmology Follow-up: Repeat dilated eye exam in 6 months given NPDR
- Foot Care: Podiatry referral; therapeutic footwear prescription; daily foot inspection education using teach-back
- Follow-up: Return in 2 weeks for medication reconciliation; monthly visits until HbA1c trending below 8%
Key Learning Points
- Approximately 36% of U.S. adults have limited health literacy, which is independently associated with a 1.5 to 3-fold increase in adverse health outcomes and hospitalizations
- The teach-back method ("Tell me in your own words how you take this medication") is the single most effective communication technique for confirming patient understanding
- Medication Possession Ratio (MPR) calculated from pharmacy refill data is an objective measure of adherence; an MPR below 80% is associated with significantly worse outcomes in diabetes and hypertension
- Medication regimen simplification (reducing pill burden, using combination products, once-daily dosing) improves adherence by 20-30% in patients with low health literacy
- End-organ damage in diabetes (retinopathy, nephropathy, neuropathy) often progresses silently; patients with adherence barriers require proactive screening protocols rather than symptom-based evaluation