| Methods |
An author not involved in the practice and patient recruitment randomized eligible patients (n = 245) stratified by age and sex to the intervention (n = 128) and control (n = 117) groups, using computer‐generated random numbers that were assigned to an anonymized list of participants. The principal investigator passed the randomization schedule on to the practice nurses shortly before the appointment for delivering the intervention. The study participants and the practice nurses were aware of the group assignment |
| Participants |
Patients had hypertension and a latest blood pressure recording of > or = to 150 mm Hg systolic and/or 90 mm Hg diastolic in the past 6 months. Patients were excluded from the study if they did not control their medication intake (such as some nursing home patients), had secondary hypertension, severe dementia or other reasons for not approaching them, such as recent bereavement |
| Interventions |
Patients in the intervention group received, in addition to usual care, a nurse‐led adherence support session lasting a maximum of 20 minutes, followed by a shorter reinforcement session (10 minutes) 2 months later. The intervention was aimed to provide an opportunity for patients to talk about any problems with their blood pressure‐lowering medication. Practice nurses investigated whether patients understood their diagnosis and agreed with the treatment process. They also addressed patient concerns with their medication and to agree to tailored strategies to resolve any medication problems. The control group received standard care delivered at their respective practices, apart from blood pressure checks at similar intervals as the participants in the intervention group. Wherever possible, these checks were carried out by another practice nurse who was not involved in delivering the intervention but all practice nurses were made aware of the risk of contamination and encouraged not to change their 'usual practice' for the control patients |
| Outcomes |
The primary adherence outcome was measured by Medication Event Monitoring System (MEMS) in the 6 months period following the intervention. Adherence was defined as 'timing compliance', which is the number of doses taken at 24 ±6‐hour intervals for a once daily regimen or 12 ±3 hours for twice daily doses, divided by the total number of days and multiplied by 100%. 2 additional measures of adherence were taken: 1) 'correct dosing', which was the percentage of days on which the correct number of doses was taken; and 2) 'taking compliance', was defined as the percentage of prescribed number of doses taken, equivalent to a 'pill count'. Systolic and diastolic blood pressure was measured at baseline as well as 1, 2, and 6 months after randomization |
| Notes |
― |
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Random sequence generation (selection bias) |
Low risk |
Central randomization; computer‐generated numbers were used for randomization. "One of the authors (TJP) who was not involved in practice and patient recruitment randomized eligible patients stratified by age and sex to the intervention and control groups using computer‐generated random numbers, which were assigned to an anonymized list of participants. The principal investigator (KS) passed the randomization schedule on to the practice nurses shortly before the appointment for delivering the intervention." (pg 146) |
| Allocation concealment (selection bias) |
Low risk |
One author not involved in the rest of the study completed randomization. "One of the authors (TJP) who was not involved in practice and patient recruitment randomized eligible patients stratified by age and sex to the intervention and control groups using computer‐generated random numbers, which were assigned to an anonymized list of participants. The principal investigator (KS) passed the randomization schedule on to the practice nurses shortly before the appointment for delivering the intervention." (pg 146) |
| 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 |
High risk |
"There is also a possibility that MEMS® may have altered patient behaviour, although it is unlikely that this effect would have persisted throughout the whole study period." "We do not know if the high adherence levels observed in this RCT were due to a self selected population, or whether the results reflect generally higher adherence levels in the UK." (pg 150) "Baseline blood pressures in both groups were close to our chosen cut‐off point of >=150/90, and only 94 out of 245 participants (39%) were 'uncontrolled'." "Lastly, with this study design there was potential for contamination." (pg 149) |
| Blinding of outcome assessment (detection bias)
Adherence measure |
Low risk |
(PRIMARY) MEMS ‐ Open RCT; practice nurses were aware of the group allocation. However, low risk proposed because it appears that practice nurses were not involved in data collection and unaware of results until completion of the study |
| Blinding of outcome assessment (detection bias)
Patient outcome |
Unclear risk |
(PRIMARY) BLOOD PRESSURE MEASUREMENT ‐ No information on whether the method of taking blood pressure was automated. There is insufficient information to permit judgment of 'Low risk' or 'High risk' |
| Blinding of participants (performance bias)
Adherence measure |
High risk |
(PRIMARY) MEMS ‐ No patient blinding. "In this open RCT both the study participants and the practice nurses were aware of the group assignment at completion of the baseline period". (pg 146) |
| Blinding of participants (performance bias)
Patient outcome |
Unclear risk |
(PRIMARY) BLOOD PRESSURE MEASUREMENT ‐ There is insufficient information to permit judgment of 'Low risk' or 'High risk' |
| Blinding of personnel (performance bias)
Adherence measure |
Unclear risk |
(PRIMARY) MEMS ‐ 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 MEASUREMENT ‐ 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) MEMS ‐ 85% follow‐up in intervention group; 80.3% in the control. Actual sample size (245) is less than power calculations (330). No significant difference in outcome between groups |
| Incomplete outcome data (attrition bias)
Patient outcome |
Unclear risk |
(PRIMARY) BLOOD PRESSURE MEASUREMENT ‐ Dropouts not equal across groups and reasons not given for all dropouts |
