Follow up and assessment of outcomes
All participants underwent two assessments: baseline (pre-randomization;
6 weeks to 6 months postpartum) and at study completion (8-12 months
postpartum) after completing at least 6 months in the study. Enrolled
participants were emailed a link to a questionnaire, which was completed
before or at the time of the first two study visits. Before March 2020,
all participants underwent a study visit either in the Magee-Womens
Clinical and Translational Research Center (CTRC) or via home research
study visits, per participant preference. After March 2020 (due to COVID
pandemic restrictions), study visits were conducted remotely. At the
time of each assessment, participants completed online questionnaires
and measured blood pressure at rest, while sitting for at least 5
minutes. Blood pressure measures were either collected by study staff
(pre-pandemic) or observed by study staff virtually using a secured Zoom
room and were repeated three times. Blood pressures were measured using
either an iHealth, Wireless Blood Pressure Monitor BP5 or an A&D UA-651
(A&D Medical; San Jose, California) automatic upper arm blood pressure
monitor, both validated by Dabl Educational Trust and the British
Society for Hypertension for use in postpartum individuals. The mean of
the three measures was used in analysis. Mean arterial pressure was
calculated with the formula [systolic BP+(2*diastolic BP)/3]. Weight
measures were collected either by study staff during an in-person visit,
pre-pandemic, or were directly observed during a remote study visit
using a study-provided iHealth or Etekcity Digital Body Weight scale.
Individuals were weighed in light clothing without shoes at the time of
the study visit for both in-person and remote study visits. Participants
in all three arms received monthly emails thanking them for their
ongoing participation.
The primary objective of this pilot study was to evaluate the
feasibility of a randomized trial of home blood pressure monitoring vs
home blood pressure monitoring plus a lifestyle intervention vs control
in the first year postpartum. Feasibility of recruitment and retention
(proportion and 95% CI) was assessed to study completion. Our
predefined measures for feasibility success included randomization of
8-10 participants per month and retention of ≥80% of participants to
one-year postpartum, with a target to complete all recruitment at the
primary site during an 18-month period and recruitment at both sites
over a 24-month period. Our primary efficacy outcome was participant
weight at the second study visit, which was chosen as a patient-centered
outcome for postpartum individuals. Secondary outcomes included: 1)
blood pressure and change in blood pressure parameters across the study;
2) participant BMI and weight change across the study, 3) adherence to
intervention, 4) self-efficacy 5) prevalence of stage 1 and 2 HTN, 6)
use of anti-hypertensive medications at study completion and 7)
prevalence of lifestyle behaviors. Stage 1 and stage 2 hypertension were
defined using the 2017 American College of Cardiology / American Heart
Association guidelines - stage 1 hypertension: systolic BP 130-139 mmHg
or diastolic BP 80-89 mmHg and stage 2 hypertension: systolic BP ≥140
mmHg, diastolic BP ≥90 mmHg or requiring anti-hypertensive
medications.(22)
Self-efficacy towards achieving a healthy diet and level of physical
activity was assessed using an adapted version of the validated Sallis
Eating Habits Confidence Survey and Exercise Confidence Survey
scales.(23) We used the Pregnancy Physical Activity Questionnaire to
assess physical activity (type, duration, and frequency) and inactivity
(sedentary behavior), which is a validated questionnaire for women that
includes activities related to caring for young children. Time spent in
each activity weekly is multiplied by its intensity to yield the average
weekly energy expenditure.(24) Sodium intake was quantified using an
adapted version of the validated Sodium Screener developed by Block
(©NutritionQuest 2011) to assess sodium intake as a continuous variable.
The Sodium Screener includes foods contributing to 80% of sodium intake
in which there are five frequency response categories—from rarely or
never (assigned a value of 0) to every day (assigned a value of 4). The
cumulative score ranges from 0 to 67, with higher scores signifying
higher sodium intakes. For women, sodium intake less than 2300 mg per
day corresponds to scores between 18-24.(25)
A core outcome set (COS) does not exist for this research subject area,
thus a COS was not used when designing the trial.