Study Population.
A total of 459 heart failure patients met the inclusion criteria and were enrolled into this study. During follow-up, 40 (8.7%) participants exited; 5 due to incomplete key data and 35 were lost to follow-up. Table 1 displays the baseline characteristics of participants. The mean age of our heart failure cohort was 46.4 ± 18.9 years and those aged ≤ 50 years constituted 55.4% of all participants. There was a female predominance (56.6%) and over two-thirds of all participants resided in urban areas. The mean BMI was 25.1 ± 5.2 and 39.4% of patients were overweight or obese. About 7.2% of participants were in NYHA functional class II while classes III and IV constituted 36.5% and 56.3% respectively. Fifty two point seven percent (52.7%) had a history of hypertension, 13.6% had diabetes, 6.7% were infected with HIV, 51.3% had renal insufficiency and 72.1% were anemic. Echocardiography revealed HHD was the predominant cause of heart failure (40.1%) followed by DCM (27.0%) and RHD (23.2%).
Table 1
Baseline characteristics of participants (N = 419)
Characteristic | All (N = 419) | Poor adherence (n = 313) | Good adherence (n = 106) | p-value |
Age Age groups <30 30–50 >50 | 46.4 (18.9) 103 (24.6%) 129 (30.8%) 187 (44.6%) | 45.5 (19.0) 82 (26.2%) 96 (30.7%) 135 (43.1%) | 49.1 (18.6) 21 (19.8%) 33 (31.1%) 52 (49.1%) | 0.09 0.19 0.94 0.28 |
Sex Male Female | 182 (43.4%) 237 (56.6%) | 139 (44.4%) 174 (55.6%) | 43 (40.6%) 63 (59.4%) | 0.50 |
Residence Urban Rural | 283 (67.5%) 136 (32.5%) | 197 (62.9%) 116 (37.1%) | 86 (81.1%) 20 (18.9%) | 0.001 |
Marital status Single Married Divorced/Widowed | 100 (23.9%) 296 (70.6%) 23 (05.5%) | 82 (26.2%) 213 (68.1%) 18 (05.7%) | 18 (17.0%) 83 (78.3%) 5 (04.7%) | 0.05 0.05 0.67 |
Education None Primary Secondary University | 16 (03.8%) 295 (70.4%) 68 (16.2%) 40 (09.6%) | 12 (03.9%) 248 (79.2%) 36 (11.5%) 17 (05.4%) | 4 (03.8%) 47 (44.3%) 32 (30.2%) 23 (21.7%) | 0.96 <0.001 <0.001 <0.001 |
Occupation None Employed/self-employed Retired | 76 (18.1%) 311 (74.3%) 32 (07.6%) | 47 (15.0%) 250 (79.9%) 16 (05.1%) | 29 (27.3%) 61 (57.6%) 16 (15.1%) | <0.01 <0.001 0.001 |
Body Mass Index BMI Categories Underweight Normal Overweight Obese | 25.1 (05.2) 11 (02.6%) 243 (58. 0%) 105 (25.1%) 60 (14.3%) | 24.8 (04.2) 7 (02.2%) 188 (60.1%) 79 (25.2%) 39 (12.5%) | 26.0 (07.4) 4 (03.8%) 55 (51.9%) 26 (24.5%) 21 (19.8%) | 0.04 0.37 0.14 0.89 0.06 |
Health insured Yes No | 93 (22.2%) 326 (77.8%) | 32 (10.2%) 281 (89.8%) | 61 (57.6%) 45 (42.4%) | <0.001 |
HF etiology DCM HHD RHD Others | 113 (27.0%) 168 (40.1%) 97 (23.2%) 41 (09.8%) | 78 (24.9%) 134 (42.8%) 72 (23.0%) 29 (09.3%) | 34 (32.1%) 35 (33.0%) 25 (23.6%) 12 (11.3%) | 0.15 0.08 0.90 0.55 |
Comorbidities Hypertension Diabetes HIV/AIDS Renal insufficiency eGFR < 15 Anemia Hb < 8 g/dL | 221 (52.7%) 57 (13.6%) 28 (06.7%) 215 (51.3%) 100 (23.9%) 302 (72.1%) 99 (23.6%) | 171 (54.6%) 39 (12.5%) 15 (04.8%) 163 (52.1%) 80 (25.6%) 234 (74.8%) 75 (24.0%) | 50 (47.2%) 18 (17.0%) 13 (12.3%) 52 (49.1%) 20 (18.9%) 68 (64.2%) 24 (22.6%) | 0.19 0.24 0.01 0.59 0.16 0.04 0.77 |
NYHA class II III IV | 30 (07.2%) 153 (36.5%) 236 (56.3%) | 19 (06.0%) 112 (35.8%) 182 (58.2%) | 11 (10.4%) 41 (38.7%) 54 (50.9%) | 0.13 0.59 0.19 |
Admission days HF-related hospitalization 1st >1 | 14.0 (13.3) 211 (50.4%) 208 (49.6%) | 13.8 (13.4) 167 (53.3%) 146 (46.7%) | 14.3 (12.8) 44 (41.5%) 62 (58.5%) | 0.74 0.04 |
Medication adherence
Overall, 337 (73.4%) were on ACEI, 122 (26.6%) on ARB, 386 (84.1%) on beta-blockers, 432 (94.1%) on diuretics, 395 (86.1%) on aldosterone antagonists, 166 (36.2%) on inotropes and 36 (7.8%) were on digoxin. Of the 419 participants eligible for assessment of medication adherence, 313 (74.7%) had poor adherence and 106 (25.3%) had good adherence. The mean number of days’ participants last took medications before the index hospitalization was 17.7 (± 6.9) days. Among participants with poor adherence, 254 (81.2%) had not taken any of their anti-failure medications within the past one-week prior admission. Inability to afford medications was the most (87.3%) reported reason for nonadherence. Other reported factors affecting adherence in this cohort included; medication side effects (8.1%), forgetfulness (53.9%), negligence (26.0%), local unavailability of drugs (18.9%) and pill burden (34.4%). Differences in age, sex, marital status, and BMI displayed similar medication adherence patterns, Table 1. However, during bivariate analyses four characteristics including education level, residence, employment status, and health insurance possession showed significant associations with adherence, Table 2. Significant variables then underwent multivariate logistic regression analysis where possession of a health insurance was found to be the strongest associated factor for adherence (OR 8.7, 95% CI 4.7–16.0, P < 0.001), Table 2.
Table 2
Factors Associated with Adherence
Control group | Comparative group | OR | 95% CI | P-value | Adj. OR | Adj. 95% CI | Adj. P-value |
age < 50 | age ≥ 50 | 0.8 | 0.5–1.2 | 0.3 | - | - | - |
Female | Male | 1.2 | 0.7–1.8 | 0.5 | - | - | - |
≥ secondary education | ≤ primary education | 5.3 | 3.3–8.6 | < 0.001 | 1.9 | 0.9-4.0 | 0.07 |
married | Single | 1.7 | 1.0-2.8 | 0.05 | - | - | - |
Employed | no employment | 0.3 | 0.2–0.5 | < 0.001 | 1.2 | 0.6–2.4 | 0.6 |
Urban | Rural | 2.5 | 1.5–4.3 | 0.001 | 2.0 | 1.1–3.7 | 0.03 |
no comorbidity | ≥ 1 comorbidity | 0.9 | 0.5–1.4 | 0.56 | - | - | - |
health insurance | not insured | 11.9 | 7.0-20.2 | < 0.001 | 8.7 | 4.7–16.0 | < 0.001 |
Rehospitalization and Mortality
Overall, 208 (49.6%) patients had a history of a prior cardiovascular-related hospitalization. During follow-up, rehospitalization rates were 32.8%, 48.1% and 53.0% at 30, 90 and 180 days respectively. Despite of similar rehospitalization rates among poor and good-adherence participants at 30-days (35.4% vs 27.2%, p = 0.12) and 90-days (51.8% vs 40.2%, p = 0.07), patients with poor adherence had significantly higher rates of rehospitalization at 180 days (57.5% vs 43.5%, p = 0.03). Participants with poor adherence displayed a 70% increased risk for rehospitalization compared to their counterparts with good adherence (RR 1.7, 95% CI 1.2–2.9, p = 0.04).
Overall, 177 (42.2%) patients survived the 180-days of follow-up. The overall mean survival days was 103.3 ± 74.8 days and participants with good adherence (140.5 ± 63.1 days) displayed a longer survival compared to their poor adherence (90.8 ± 74.3 days) counterparts, p < 0.001. Mortality rate was 30.8%, 48.7% and 57.8% at 30, 90 and 180 days respectively. Regardless of the assessment time, participants with poor adherence displayed superior mortality compared to those with good adherence i.e. 37.1% vs 12.3% at 30 days, 56.6% vs 25.5% at 90 days, and 65.5% vs 34.9% at 180 days; all p < 0.001). Additionally, we performed subgroup analyses to assess for all-cause mortality by adherence status. In all 19 characteristics involved in subgroup analyses, participants with poor adherence had inferior survival rates compared to their counterparts with good adherence, Fig. 1. More interestingly, even within the subgroup of those who possessed a health insurance, it was observed that poor adherence participants fared worse compared to good adherence controls, (HR 1.6, 95% CI 1.0-2.4, p = 0.05).