Table 3.
Summary of results from the studies
| Reference | Survival analysis | Other analyses | Control | Significant | Nonsignificant | Comments |
|---|---|---|---|---|---|---|
| Jones et al (1995) | ANOVA Compare continuers vs switch/discontinue | Continuers: nr of GP visits inc, nr of AHT prescriptions dec (significance levels not given) | Frequency of continuation decreased with duration | |||
| Monane et al (1997) | Logistic for good compliance at 1 y | Age (3 groups), sex, race, start year | OR (95% CI) | Thiazide dose | Analysis repeated for patients with > 1 prescription and with CHF/CAD – same | |
| Thiazide 1.0, BB 1.4 (1.2, 1.7), CCB 1.7 (1.5, 2.1), ACE 1.9 (1.6, 2.1), CHF/CAD 1.2, > 8 GP visits 2.2, > 8 other medicines 0.8, redeem at > 1 pharmacy 0.4 | ||||||
| Rizzo and Simons (1997) | OLS for 1 y compliance | Duration dec, BB duration inc, CCB duraction inc, ACE duration inc, age inc, white inc, medical resources inc, CHF inc | Sex, asthma, COPD,diabetes, renal failure, angina, LVH, AMI, PAD, TIA | Significance level 0.01 Also OLS regression for costs | ||
| Okano et al (1997) | None | Tables for rates of compliance only | ||||
| Bloom (1998) | Logistic for persistence at 12 mo | OR (95% CI) | Sex – OR is 1.08 (1.02–1.15); clinically uncertain and don’t specify whether male vs female or vice versa | |||
| Thiazide 0.36 (0.30, 0.43), BB 0.56 (0.47, 0.68), CCB 0.62 (0.51, 0.74), ACE 0.81 (0.68, 0.97), AT2 1.00, age > 65 y 1.00, age 40–65 y 0.79, age < 40 y 0.32; > 1 dose/day 1.40 | ||||||
| Caro, Salas, et al (1999) | Kaplan-Meier, log-rank test | Logistic for 12 mo persistence | OR | Log-rank test for new vs established HT significant p < 0.001 | ||
| Age > 60 y 1.11, female 1.16, established HT 10.73, > 3 other medicines 1.29, > 5 GP visits 1.59, hospital admission 0.75 | ||||||
| Caro, Speckman, et al (1999) | Kaplan-Meier, log-rank test for drug class | Logistic for 12 mo persistence | Age, sex, GP visits, other medicines, hospitalization | OR (95% CI) | Log-rank test for drug class significant p < 0.001 | |
| Diuretic 1.00, BB 1.25 (1.12, 1.39), CCB 1.51 (1.36, 1.69), ACE 1.92 (1.76, 2.09) | ||||||
| Benson et al (2000) | ANCOVA for median duration between drugs | Men significantly longer therapy overall and for atenolol. quinapril, HCTZ + triamterene | Drug type | Duration difference men vs women may not be clinically significant | ||
| Dezii (2000) | % persistent plotted vs month | Test single tablet vs 2 separate drugs at 6 and 12 mo; test not stated but significant (p < 0.05) | ||||
| Bourgalt et al (2001) | Cox PH for time to first modification of initial therapy | Poisson regression for modification rates | Age inc, female inc, BB vs others dec, combination vs other inc | Hazard ratios not given in paper | ||
| Conlin et al (2001) | % persistent each 6 mo plotted vs time | OLS regression for difference in persistence rate over time (12–48 mo) | Predicted difference in persistence rates vs AT2s: Thiazide –68.8%, BB –34.5% CCB –20.8%, ACE –10.1%; p < 0.001 | Log transform persistence rate | ||
| Ren et al (2002) | OLS regression for compliance (over 2 y) | Predictors of compliance: age inc, nr of medications inc, input to treatment decisions inc, doctor age dec, speciality care resident vs primary care, other healthcare provider vs doctor | Race, education > 13 y, doctor’s sex, practice size | |||
| Degli Esposti E et al (2002) | Cox PH for duration first–last prescription | Hazard ratios for discontinuation: age (1 y) 0.976 (0.974, 0.978), female 0.894 (0.832, 0.961), diuretic 2.624 (1.992, 3.457), BB 1.869 (1.414, 2.472), CCB 2.073 (1.574, 2.731), ACE 1.577 (1.198, 2.076), AT2 1.00, GP age 1.006 (1.002, 1.011), GP female 0.911 (0.836, 0.992) | Comorbidity, previous hospitalization, district, practice size | Patient age then drug class have most influence on persistence | ||
| Marentette et al (2002) | Persistence plotted vs time for drug classes | Repeated measures ANCOVA for relationship between drug class and persistence | Age, female, drug class – all pairwise comparisons significant except CCB and BB, female ˙ drug class, age ˙ drug class | Increasing age increases persistence, mainly because younger patients especially taking BB, CCB, diuretics | ||
| Wang et al (2002) | Ordinal logistic regression for PDC tertiles | Age, sex, race, education, employment, treat, site, thiazide use, comorbidities | OR (95% CI) | Health beliefs, knowledge of HT, social support, satisfaction, alcohol use, smoking, socially desirable responding depression diagnosis | ||
| Depression (1 point on 15-point scale) 0.93 (0.87, 0.99), external locus of control (6-point scale) 1.15 (0.99,1.33) | ||||||
| Hasford et al (2002) | Kaplan-Meier for differences in drug classes Cox PH for time on initial monotherapy | Hazard ratios not given | ||||
| Patients on irbesartan significantly more likely to persist with initial therapy than all others | ||||||
| Degli Esposti L et al (2002) | Cox PH for time to discontinuing initial AHT (additions included) OH assumption tested | ANOVA to compare patient ages in continuers, switchers, discontinuers and in drug classes | Hazard ratios for discontinuation: age (+1 y) 0.982 (0.981, 0.983), AT2 1.00, diuretics 2.442 (2.044, 2.917), BB 1.525 (1.272, 1. 829), CCB 1.913 (1.602, 2.284), ACE 1.695 (1.419, 2.025), heart disease 1.531 (1.238, 1.894), diabetes 1.509 (1.242, 1.834), previous CVD hospitalization 1.524 (1.394, 1.667), ≥ 2 comorbidities 1.571 (1.334, 1.851) | Sex, asthma drugs | ||
| Wogen et al (2003) | Cox PH for time to discontinuation of any AHT | OLS regression for compliance (PDC) | Hazard ratios for discontinuation: p < 0.0001 in all cases unless stated: age 0.933, male 0.954, valsartan 1.00, amlodipine 1.333, lisinopril 1.446, diuretics 1.103, diuretic combination 1.544, BB 1.131, nitrates 1.137, LLDs 0.743, chronic disease score 1.013, digitalis 1.049 (p = 0.0012), antiplatelets 1.032 (p = 0.018) | |||
| Taylor and Shoheiber (2003) | No modeling; chi-square and t-tests | Stratified for age group; morbidity score (Charlson index) | Amlodipine/benazepril vs ACE + CCB | Sequential prescriptions of ACE, CCB considered for MPR | ||
| Degli Esposti et al (2004) | Cox PH for time to discontinuing initial AHT | OLS regression for costs | Hazard ratios for discontinuation: age (+1 y) 0.978, diuretic 1.853, CCB 1.663, ACE 1.386, AT2 1.00, heart disease 1.666, diabetes 1.394, previous CVD hospitalization 1.507, ≥ 2 comorbidities 1.630 | Sex, asthma drugs |
Abbreviations: ACE, angiotensin-converting enzyme inhibitor; BB, β-blocker; CCB, calcium channel blocker; AT2, angiotensin-II antagonist; AHT, antihypertensive; LLD, lipid-lowering drug; CVD, cardiovascular disease; HF/CHF, heart failure; CAD, coronary artery disease; HT, hypertension; COPD, chronic obstructive pulmonary disease; LVH, left ventricular hypertrophy; AMI, acute myocardial infarction; PAD, peripheral arterial disease; TIA, transient ischemic attack; PDC, proportion of days covered; MPR, medication possession ratio; OLS, ordinary least squares; PH, proportional hazards; ANCOVA, analysis of covariance; ANOVA, analysis of variance; OR, odds ratio; CI, confidence interval; dec, decrease; inc, increase; mo, month; y, year.