| Methods |
Random allocation, 2 x 2 factorial design, no indication of concealment |
| Participants |
Male steel company employees who exhibited persistently elevated diastolic blood pressure on repeated examination (at or above 95 mmHg (5th phase)), were free of secondary forms of hypertension, were taking no daily medication, and had not been prescribed antihypertensive medications for at least 6 months before the trial were eligible for the study |
| Interventions |
Subjects in augmented convenience saw company physicians, rather than their family physicians, for hypertensive and follow‐up care during paid working hours. The second intervention, mastery learning, was designed to give the facts about hypertension, its effects upon target organs, health, and life expectancy, the benefits of antihypertensive therapy, the need for adherence with medications and some simple reminders for taking pills (this information was provided in a slide‐tape format, and reinforced by a secondary‐school graduate 'patient educator') |
| Outcomes |
Adherence was calculated by comparing the number of tablets prescribed with medications still on hand, by the semi‐quantitative identification of drugs and metabolites in the urine, by the identification of characteristic changes in serum potassium and uric acid in men on thiazide drugs. Adherence is reported in terms of the per cent of medication prescribed for the 6th month which was removed from the bottle and, presumably, consumed by the patient. Patients whose pill counts were consistent with adherence levels of 80% or more were considered 'compliant'. Blood pressure control was assessed by trained observers. Only patients whose diastolic blood pressure was below 90 mm Hg at 6 months would be designated as being 'at goal blood pressure'. Outcome assessors were blinded to study group |
| Notes |
― |
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Random sequence generation (selection bias) |
Unclear risk |
Method of sequence generation not described: "After stratification for factors likely to influence either compliance or the probability that their blood‐pressure could be controlled (prior antihypertensive therapy, age, other illness, and severity of hypertension), they were randomly allocated into a factorial design which permitted the simultaneous evaluation of the ability of two independent strategies to enhance compliance with antihypertensive therapy." (pg 1205) |
| Allocation concealment (selection bias) |
Low risk |
The author indicated allocation was concealed |
| Selective reporting (reporting bias) |
Unclear risk |
No protocol available; although it appears that everything was reported it is difficult to determine this without a protocol |
| Other bias |
Low risk |
The study seems to be free of other types of bias |
| Blinding of outcome assessment (detection bias)
Adherence measure |
Low risk |
(PRIMARY) PILL COUNT ‐ The men were re‐assessed by staff who were unaware of the experimental group allocation (pg 1206) |
| Blinding of outcome assessment (detection bias)
Patient outcome |
Low risk |
(PRIMARY) BLOOD PRESSURE ‐ Outcome assessors were blinded |
| Blinding of participants (performance bias)
Adherence measure |
High risk |
(PRIMARY) PILL COUNT ‐ The author noted that the patients were not blinded |
| Blinding of participants (performance bias)
Patient outcome |
Low risk |
(PRIMARY) BLOOD PRESSURE ‐ The author has noted that the patients were not blinded but blinding would likely not impact outcome |
| Blinding of personnel (performance bias)
Adherence measure |
Low risk |
(PRIMARY) PILL COUNT ‐ The men were re‐assessed by staff who were unaware of the experimental group allocation (pg 1206) |
| Blinding of personnel (performance bias)
Patient outcome |
Unclear risk |
(PRIMARY) BLOOD PRESSURE ‐ No information on whether the method of taking blood pressure was computerized. 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 ‐ Reasons for dropouts were not provided |
| Incomplete outcome data (attrition bias)
Patient outcome |
Unclear risk |
(PRIMARY) BLOOD PRESSURE ‐ Reasons for missing data were not provided |
