| Methods |
Random allocation in a 2 x 2 factorial design. No statement concerning concealment of randomization |
| Participants |
Volunteers from shopping center blood pressure screening in Canada, with follow‐up by usual family doctors. Men and women aged 35 to 65 who had been receiving antihypertensive medications for at least 1 year, but whose diastolic blood pressure had remained elevated |
| Interventions |
The interventions consisted of (1) self recording and monthly home visits, (2) self recording only, (3) monthly home visits, and the control group consisted of (4) neither self recording nor home visits. Subjects in groups (1) and (2) received a blood pressure kit and instruction in self recording. Patients in the self recording groups were to keep charts of their daily blood pressure readings and were instructed to bring these charts to their physician at each appointment. Subjects in groups (1) and (3) had their blood pressure measured in their homes every 4 weeks, and the results were reported to both the patient and the physician |
| Outcomes |
Adherence with therapy was assessed by interview and pill counts (the percentage of prescribed pills that had been consumed was estimated by comparing pills on hand at a home visit with prescription records of pills dispensed and the regimen prescribed). Changes in mean diastolic blood pressure (mm Hg) were assessed. Since the initial blood pressure bears an important relation to the change in blood pressure over time, the change scores were adjusted for differences in entry values by covariance analysis. Outcome assessors were blinded to study group |
| Notes |
― |
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Random sequence generation (selection bias) |
Unclear risk |
Not enough information given in the article. (pg 1035) Once their informed consent was obtained the subjects were stratified for age (less than 45 years old and 45 or older) and sex, then assigned at random to one of 4 groups in a 2 x 2 factorial design: (1) self recording and monthly home visits; (2) self recording only; (3) monthly home visits; and (4) neither self recording nor monthly home visits |
| Allocation concealment (selection bias) |
Unclear risk |
Not enough information given in the article. (pg 1035) Once their informed consent was obtained the subjects were stratified for age (less than 45 years old and 45 or older) and sex, then assigned at random to one of 4 groups in a 2 x 2 factorial design: (1) self recording and monthly home visits; (2) self recording only; (3) monthly home visits; and (4) neither self recording nor monthly home visits |
| Selective reporting (reporting bias) |
Unclear risk |
No protocol available |
| Other bias |
Unclear risk |
None noted but unclear |
| Blinding of outcome assessment (detection bias)
Adherence measure |
Unclear risk |
(PRIMARY) SELF REPORT ‐ INTERVIEW ‐ Adherence data were collected at subject's residence by an investigator, most likely unblinded. (pg 1035) "Six months later all subjects were visited twice within 1 to 3 days by the visitor who had previously seen them. Standardized blood pressure measurements were made and compliance with therapy was assessed by interview and pill count (the percentage of prescribed pills that had been consumed was estimated by comparing pills on hand with prescription records of pills dispensed and the regimen prescribed)." |
| Blinding of outcome assessment (detection bias)
Patient outcome |
Unclear risk |
(PRIMARY) BLOOD PRESSURE ‐ No mention of blinding |
| Blinding of participants (performance bias)
Adherence measure |
High risk |
(PRIMARY) SELF REPORT ‐ INTERVIEW ‐ Participants would have been aware of their group membership |
| Blinding of participants (performance bias)
Patient outcome |
Low risk |
(PRIMARY) BLOOD PRESSURE ‐ Blood pressure unlikely to be influenced by patient blinding |
| Blinding of personnel (performance bias)
Adherence measure |
Unclear risk |
(PRIMARY) SELF REPORT ‐ INTERVIEW ‐ Blinding measures not described except for the independent investigator measuring BP. Other personnel may be unblinded |
| Blinding of personnel (performance bias)
Patient outcome |
Unclear risk |
(PRIMARY) BLOOD PRESSURE ‐ No mention of blinding |
| Incomplete outcome data (attrition bias)
Adherence measure |
Low risk |
(PRIMARY) SELF REPORT ‐ INTERVIEW ‐ Small rate of attrition ‐ 4/140. Reasons for the missing data unlikely to be connected with outcome |
| Incomplete outcome data (attrition bias)
Patient outcome |
Low risk |
(PRIMARY) BLOOD PRESSURE ‐ Small rate of attrition ‐ 4/140. Reasons for the missing data unlikely to be connected with outcome |
