Table 2

Results of age subgroup analyses on associations between age and health literacy, and age and medication adherence

Authors, yearAge subgroups reportedAge subgroup analyses
Lee et al, 201335NANone conducted.
Lee et al, 20173665–74 (57.0%)
≥75 (43.0%)		No significant differences in MA between age groups (χ²=0.391, p=0.835).
Lu et al, 201941≤60 (21.5%)
61–70 (43.0%)
71–80 (29.7%)
>81 (5.7%)		Patients with limited HL were significantly older than those with adequate HL (p<0.05).
Age was not a significant predictor for limited HL in ≥81-year-old patients compared with

  • Patients ≤60 years old (AOR (95% CI)=0.64 (0.24–1.72), p=0.380)

  • Patients 61–70 years old (AOR (95% CI)=1.19 (0.49–2.88), p=0.694)

  • Patients 71–80 years old (AOR (95% CI)=0.97 (0.40–2.40), p=0.955).


Age was not a significant predictor for medication nonadherence in ≥81-year-old patients compared with

  • Patients ≤60 years old (AOR (95% CI)=0.67 (0.19–2.36), p=0.534)

  • Patients 61–70 years old (AOR (95% CI)=1.43 (0.49–4.17), p=0.518)

  • Patients 71–80 years old (AOR (95% CI)=1.02 (0.34–3.09), p=0.970).

Reading et al, 201937<65 (27.2%)
65–74 (30.8%)
75–84 (30.5%)
≥85 (11.5%)		Nonadherence to medication significantly differed according to age (p<0.001).
Age was a significant predictor for nonadherence to medication in <65-year-old patients compared with

  • Patients 65–74 years old (AOR (95% CI)=0.68 (0.55–0.83), p<0.001)

  • Patients 75–84 years old (AOR (95% CI)=0.67 (0.53–0.84), p<0.001).


Age was not a significant predictor for nonadherence to medication in <65-year-old patients compared with

  • Patients≥85 years old (AOR (95% CI)=0.86 (0.64–1.16), n.s.).

Saqlain et al, 20194465–75 (84.7%)
76–85 (11.1%)
>85 (4.2%)		No significant differences in MA between age groups (χ²=1.631, p=0.442).
Seong et al, 20193865–70 (32.1%)
70–79 (45.5%)
≥80 (22.4%)		Adherence to medication significantly differed with respect to age (χ²=15.15, p<0.001).
Age was a significant predictor for nonadherence to medication in ≥80-year-old patients (univariate regression) compared with

  • Patients≤79 years old (OR (95% CI)=2.33 (1.291–4.207), p=0.005, univariate).


Age was not a significant predictor for nonadherence to medication in ≥80-year-old patients (multivariate regression) compared with

  • Patients≤79 years old (OR (95% CI)=1.24 (0.621–2.459), p=0.546, multivariate).

Shehadeh-Sheeny et al, 20134560–65 (21.5%)
66–75 (54.1%)
76–85 (24.4%)		No significant differences in MA between age groups (p=0.23).
Song and Park, 20203965–69 (38.8%)
70–79 (43.1%)
≥80 (18.1%)		Adherence to medication significantly differed with respect to age (Z=8.37, p<0.001). Post hoc analysis showed higher MA in 65–69 year-old adults (M=5.1 (2.3)) compared with 70–79 (M=4.0 (2.0)) and ≥80-year-old adults (M=3.0 (1.9)), respectively.
Wannasirikul et al 20164660–65 (52.7%)
66–70 (47.3%)		None conducted.

  • AOR, adjusted OR; HL, health literacy; MA, medication adherence; NA, not available/ not reported.