Clinical Trial Details
— Status: Completed
Administrative data
NCT number |
NCT02892929 |
Other study ID # |
16-0225 |
Secondary ID |
|
Status |
Completed |
Phase |
N/A
|
First received |
|
Last updated |
|
Start date |
September 2016 |
Est. completion date |
July 2019 |
Study information
Verified date |
April 2021 |
Source |
Hospital de Clinicas de Porto Alegre |
Contact |
n/a |
Is FDA regulated |
No |
Health authority |
|
Study type |
Interventional
|
Clinical Trial Summary
This randomized clinical trial was designed to test the effectiveness of Motivational
Interviewing in lowering blood pressure during six months follow-up.
Description:
The lead researcher is a cardiovascular nurse specialist with 10 years of experience in the
care of patients with heart disease and she will be responsible for the application of the
Motivational Interviewing (MI) technique in the appointments for the intervention group. She
also participated in an intensive workshop about MI, which followed the recommendations of
the Motivational Interviewing Network of Trainers19 in 2013, and more recently, in 2015 and
2016, she participated in two workshops on advanced MI techniques. During the study there
will be monthly supervision with another specialist. The training and the supervision will be
the responsibility of a PhD researcher in Psychiatry with consistent experience on
Motivational Interviewing and training conducted in the United States with Miller and
Rollnick.
The sample size was calculated with WinPepi 11.20 software. Sample size was estimated in 100
patients, 50 in the intervention group (IG) and 50 in the control group (CG), considering a
difference of 8 mmHg between groups, standard deviation of 14 mmHg, 80% power, and alpha of
0.05. Adding 20% of losses the sample will have 120 patients, 60 for each group.
Hypertension outpatients of Hospital de ClĂnicas de Porto Alegre (HCPA) will be identified by
the appointment book and invited to participate in the study through telephone calls. The
first appointment will consist in obtaining the ICF and confirmation of eligibility. After
ICF's signing and confirmation of eligibility, the patient will be randomized to one of the
groups. Participants of both groups will attend monthly appointments: first appointment (D0),
appointment of 30, 60, 90, 120, and 150 days, totaling six individual encounters, previously
arranged in the Clinical Research Center (CRC) of HCPA, with an average duration of 30
minutes.
The randomization list was generated through the website www.randomization.com. The list will
be in possession of a professional of the research group, however non-participant of this
project. The allocation group of each patient will be hidden by opaque envelopes of identical
appearance.
The researcher responsible for the application of the MI technique and the one responsible
for the conduct of conventional appointments will be blinded to the outcomes of the study;
therefore, the application of structured questionnaires, scales, and assessment of other
variables of the study will be carried out by a researcher unblinded to the outcomes.
Statistical analysis:
Continuous variables will be expressed as mean standard deviation or median and interquartile
range (25 and 75 percentile). Categorical variables will be expressed in absolute and
percentage numbers. Chi-square will be used for associations between sociodemographic and
clinical variables with the scores of the Self-Care Scale. The comparison of the quantitative
variables between groups will be conducted by the Student's t-test or Mann-Whitney test,
according to data's distribution. The values of systolic blood pressure (SBP) and diastolic
blood pressure (DBP) during the study, as well as the scores of the Self-Care Scale will be
analyzed by the Generalized Estimating Equations (GEE) with Bonferroni correction. The
pressure differences between both groups during the treatment will be analyzed by ANOVA test
for repeated measurements. Analysis of Covariance will be conducted to adjust possible
differences regarding the basal pressure. The 5% level of significance will be adopted and
the data will be analyzed in the Statistical Package for the Social Sciences (SPSS) v.20
(Chicago, Illinois, USA).