Table 2.
Clinical consequences of adherence or nonadherence to antihyperglycemic medications
| Study | Diabetic populationa | Overview of study design | Results |
|---|---|---|---|
| Glycemic control | |||
| Adams et al30 | Type 2 | Population-based study using claim-based data | More frequent refills of oral antihyperglycemics were associated with lower average HbA1c |
| Cobden et al32 | Type 2b | Population-based study using claim-based data | Incidence of hypoglycemia ↓ almost two-thirds (P<0.05) among patients with an MPR ≥80% |
| Egede et al19 | Type 2 | Large prospective longitudinal study (mean follow-up 5.4 years) | Glycemic control worsened over time in patients with poor adherence to oral antihyperglycemics and/or insulin. Conversely, there was a significant (P<0.001) reduction in HbA1c of 0.24% for every 10% ↑ in MPR |
| Pladevall et al23,31 | Type not specified | Population-based study using claim-based data | A 10% ↑ in nonadherence to metformin was associated with a 0.14% ↑ in HbA1c |
| Hospitalization and mortality | |||
| Ayyagari et al7 | Type 2c | Population-based study using claim-based data | Patients adherent to insulin had a significantly (P<0.001) lower predicted rate of hospitalization than those not adherent to insulin; insulin-pen use also significantly (P<0.001) ↓ predicted hospitalization vs syringe and vial use |
| Boye et al34 | Type 2 (≥65 years of age) | Population-based study using claim-based data | Adherence to all antihyperglycemic agents (assessed by PDC over 3 years) significantly (P<0.001) reduced the odds of hospitalization or ER visit, length of stay in hospital, and risk of an acute complication |
| Curtis et al35 | Type 2 | Population-based study using claim data | Adherence to all antihyperglycemic agents (assessed by PDC over 3 years) significantly (P<0.001) reduced the odds of hospitalization or ER visit, number of hospitalizations or ER visits, and length of stay in hospital |
| Ho et al33 | Type not specified | Population-based study using claim data | Rates of hospitalization and all-cause mortality were significantly (P<0.001) higher for poorly adherent vs adherent patients (based on a summary PDC for filled prescriptions of oral antihyperglycemics, antihypertensives, and statins) |
| Juarez et al36 | Type not specified | Population-based study using claim data | Adherence to antihyperglycemics (oral and/or insulin), lipid-lowering agents, and antihypertensives (assessed by PDC over 4 years) was associated with ↓ odds of hospitalization or ER visits by the third year |
| Nguyen et al37 | Type 2d | Population-based study using claim data | Adherence to GLP1-receptor agonist (assessed by PDC over 1 year) significantly (P<0.001) reduced the odds of hospitalization for any reason or related to diabetes |
| Renal complications | |||
| Chang et al8 | Type 2 | Population-based study using claim data | Nonadherence to oral antihyperglycemic medication (assessed by MPR over a mean follow-up of 5.7 years) was associated with ↑ risk of ESRD (HR 1.11, 95% CI 1.01–1.23) vs adherence |
Notes:
a
Where reported, most studies used ICD-9-CM codes 250.xx to identify patients with diabetes;
b
all patients had switched from conventional insulin administration using a syringe and vial to a prefilled insulin pen;
c
all patients were initiating insulin treatment;
d
all patients were initiating treatment with GLP1-receptor agonist.
Abbreviations: ER, emergency room; ESRD, end-stage renal disease; GLP1, glucagon-like peptide 1; HbA1c, glycosylated hemoglobin; MPR, medication-possession ratio; PDC, proportion of days covered.