| Methods |
Patients (n = 636) were randomly allocated to receive 1 of the 2 interventions, the telephone intervention (n = 216) or the mail intervention (n = 212), or usual care (n = 212). Allocation concealment was not specified |
| Participants |
Patients were eligible for participation in the trial if the following criteria were met: (i) Outpatients of either sex and between 18 and 80 years of age; (ii) newly diagnosed or uncontrolled phase I and II hypertension (JNC‐VI criteria) requiring antihypertensive treatment; (iii) provision of patient informed consent in writing
Patients were excluded if they met any of the following criteria: (i) Patients who at the start of the study required 2 or more antihypertensive drugs for hypertension control; (ii) acute myocardial infarction; (iii) secondary hypertension; (iv) known side effects and contraindications to the use of angiotensin AT1 inhibitors; (v) pregnant or breastfeeding women; (vi) patients with conditions capable of interfering with the study; (vii) patients planning to donate blood; (viii) participants in other research studies; (ix) patients cohabiting with another person taking the same antihypertensive medication
Study withdrawal criteria were as follows: (i) Inadequate therapeutic effect requiring an increase of more than 20% in the scheduled number of visits; (ii) patient decision not to continue with the study and/or schedule follow‐up visits; (iii) concomitant illnesses or adverse effects that in investigator opinion, the patient needs be withdrawn from the study |
| Interventions |
Participants allocated to the telephone intervention group (TIG) received a controlled intervention in the form of 3 telephone calls: the first 15 days after the inclusion visit; the second and third being one week after visits 3 and 4. The telephone intervention was made by 2 expert nurses in this type of interventions. During the calls to patients in this group, the patients were reminded of scheduled visits and asked about the name, dosage, and timing of their antihypertensive medication, and the number of remaining tablets. Patients were informed, according to the number of tablets in their possession, if they had good or poor compliance. In the event of good compliance, the patients were congratulated and encouraged to continue adhering to therapy. In the event of noncompliance, the patients were encouraged to comply, and the associated benefits were explained. For participants who were allocated to the mail intervention group (MIG), they received 3 mailed communications at home: the first 15 days after the inclusion visits; the second and third, being one week after visits 3 and 4; in order to promote compliance through health education in hypertension, reinforce compliance, and remind the subjects of the scheduled visits. The mailed messages included information about the following hypertension aspects: what is hypertension?; diagnosis of hypertension; symptoms; related risk factors; why is necessary to treat the hypertension?; what is the hypertension treatment?; and information about the correct taking of medication. Patients who were allocated to the control group (CG) received the center's routine primary care intervention and did not receive any additional intervention to improve adherence |
| Outcomes |
Compliance was assessed using a pill count. Percentage compliance (PC) was calculated from the following formula: PC = (total no. of presumably consumed tablets/total no. that should have been consumed)*100. Compliance was accepted if it was in the range of 80% to 110%. The study final PC for each patient was defined as the cumulative PC at the end of follow‐up (at the end of the last visit or at the time of withdrawal), while the monthly PC was taken to be the PC recorded between one follow‐up visit and the next. Blood pressure was measured as the clinical endpoint during the scheduled visits by the primary care physician. The final blood pressure reading was taken as the mean of the 2 measurements made |
| Notes |
― |
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Random sequence generation (selection bias) |
Low risk |
The author notes that they used a random numbers table |
| Allocation concealment (selection bias) |
Low risk |
Centralized allocation. The "intervention group designation was carried out by two investigators not included as field investigators, and on a centralized basis." No other description of allocation concealment is described. But marked low because the process of randomization was centralized, performed by 2 investigators not included as field investigators, away from the study sites |
| Selective reporting (reporting bias) |
Low risk |
The author notes, "...study explores whether the intervention is targeted to patients with hypertension, based on two strategies adapted to our setting (''telephone intervention'' and "mail intervention"), is effective in improving compliance. This question answered in the study." |
| Other bias |
Low risk |
The author notes that the population included in this study consists of newly diagnosed and uncontrolled hypertensive patients. These 2 populations are different, and indeed there is a high percentage of uncontrolled hypertensive patients that could not be controlled because of poor adherence. Also, we should bear in mind that the generalization of these study findings excludes patients with previous acute myocardial infarction seen in primary care centers |
| Blinding of outcome assessment (detection bias)
Adherence measure |
Low risk |
(PRIMARY) PILL COUNT ‐ Those collecting the data were stated to be blinded. "The field technicians were blinded to the group assignments until after the baseline measurements were completed. Subjects assigned to the TLC intervention group were trained to use TLC and an automated sphygmomanometer. All participants received a final home visit 6 months after entry into the study when all study measurements were re‐administered by technicians blinded to the study assignments." (pg 286) |
| Blinding of outcome assessment (detection bias)
Patient outcome |
Unclear risk |
(PRIMARY) BLOOD PRESSURE ‐ Blinding of primary health physician not mentioned in the article. "The field technicians were blinded to the group assignments until after the baseline measurements were completed." (pg 286) |
| Blinding of participants (performance bias)
Adherence measure |
Unclear risk |
(PRIMARY) PILL COUNT ‐ Patients would have been aware of the intervention. However, "at the follow‐up and final visits, BP, weight and tablet count were recorded – the investigator being required to show discretion in counting the tablets, in order to avoid patient bias." |
| Blinding of participants (performance bias)
Patient outcome |
Low risk |
(PRIMARY) BLOOD PRESSURE ‐ This is an objective measure of outcome |
| Blinding of personnel (performance bias)
Adherence measure |
Unclear risk |
(PRIMARY) PILL COUNT ‐ No information on blinding given. There is insufficient information to permit judgment of 'Low risk' or 'High risk' |
| Blinding of personnel (performance bias)
Patient outcome |
Unclear risk |
(PRIMARY) BLOOD PRESSURE ‐ No information on blinding given. There is insufficient information to permit judgment of 'Low risk' or 'High risk' |
| Incomplete outcome data (attrition bias)
Adherence measure |
Unclear risk |
(PRIMARY) PILL COUNT ‐ No information given about why the dropouts occurred |
| Incomplete outcome data (attrition bias)
Patient outcome |
Unclear risk |
(PRIMARY) BLOOD PRESSURE ‐ Reasons for dropout were not given |
