Evaluation of a Patient Portal Intervention for Diabetes: A Two-arm, Parallel-Design, Pilot Randomized Controlled Trial
Phase: NA
Conditions: Diabetes Mellitus, Type 2
Sponsor: Vanderbilt University Medical Center

 
 
 
 
 
 
 
 
 
 
 
Evaluation of a Patient Portal Intervention for Diabetes: A Pilot Randomized 
Controlled Trial 
 
NCT03947333 
 
Protocol and Statistical Analysis Plan 
 
March 8, 2020 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 
 
Table of Contents: 
 
Study Schema 
1.0 
Background 
2.0 
Rationale and Specific Aims 
3.0 
Inclusion/Exclusion Criteria 
4.0 
Enrollment/Randomization 
5.0 
Study Procedures 
6.0 
Statistical Analysis Plan 
 
 
 

 
 
1.0 
Background 
Diabetes is a leading cause of kidney failure, heart disease, stroke, visual impairment, 
and non-traumatic lower limb amputations. Diabetes self-management can prevent or 
delay many diabetes-related complications, yet patients struggle to consistently engage 
in recommended self-care behaviors. Patient activation (i.e., knowledge, skills and 
confidence to manage their own health and care) is essential to achieving optimal 
diabetes self-management and is associated with lower costs. 
 
By providing an engaging and convenient means to track and visualize health data, 
obtain education and guidance, and connect patients and doctors, patient portals offer a 
promising platform to increase patient activation, enhance care and promote self-
management while overcoming the limitations of costly and difficult to scale face-to-face 
interventions. We recently applied user-centered design sprint methodology and key 
strategies for patient engagement to develop a patient web portal intervention for 
patients with diabetes called the My Diabetes Care (MDC; formerly Diabetes 
Dashboard).   
 
MDC is embedded within an established patient portal, My Health at Vanderbilt (MHAV).  
MDC is a multi-faceted intervention designed to help patients better understand their 
diabetes health data as well as support self-management. The MDC uses infographics 
to visualize and summarize patients' diabetes health data, incorporates motivational 
strategies (e.g., social comparisons), and provides literacy-level appropriate educational 
resources. MDC is grounded in a well-established Chronic Care Model (CCM) adapted 
for eHealth (i.e., healthcare practices supported by electronic processes and 
communication). By levering elements within the Model’s five domains (self-
management support, delivery system design, decision support, clinical information 
systems, and eHealth education), MDC has the potential create more informed and 
activated patients leading to improved outcomes.   
 
2.0 
Rationale and Specific Aims 
This study aims to evaluate the effects of MDC on patient activation in adult patients 
with type 2 diabetes mellitus (T2DM). In addition, we plan to explore secondary 
outcomes, including system use and usability, and the effects of MDC on diabetes self-
efficacy, knowledge, self-care, medication adherence, distress, and clinical endpoints. 
The study will serve as a pilot for a larger definitive trial evaluating the effect of MDC on 
clinical endpoints. We will recruit patients into two study arms which will receive: (1) 
usual care arm and (2) the intervention arm. Participants in Arm 1 (usual care) will have 
access to the standard version of My Health at Vanderbilt (MHAV), the Vanderbilt 
patient portal. Participants in Arm 2 will be provided access to a version of MHAV 
embedded with the intervention, MDC. Participants in both arms will be told the purpose 
of the study is to determine satisfaction with two versions of MHAV among patients with 
diabetes. The study will utilize questionnaires to quantify participants’ responses to 
MDC in comparison to usual care. Each participant will be enrolled in the study for six 
months.  
 
3.0 
Inclusion/Exclusion Criteria 

 
 
Participants will be eligible for the study if they are a patient at one of the 14 
participating VUMC-affiliated adult primary care clinics and have T2DM, are currently 
being treated with at least one diabetes medication, are able to speak and read in 
English, are age 21 or over, have an existing MHAV account, and have reliable access 
to a desktop or laptop computer with internet access. 
 
We will exclude patients living in long term care facilities, patients with known cognitive 
deficits, patients with severe visual impairment, and patients currently participating in 
another diabetes related research study. 
 
4.0 
Enrollment/Randomization 
Participants will be able to complete an electronic consent form and enroll online via 
Research Electronic Data Capture (REDCap™) version 5.0.8.  The study coordinator 
will verify all eligibility criteria prior to randomization. The procedure and risks will be 
explained to the participants and the consent form signed as per standard practice. All 
participants are randomly assigned to one of two groups: (1) intervention group which 
will have access to a version of MHAV embedded with the MDC or (2) usual care group 
which will have access to the currently available version of MHAV. Participants 
randomized to the intervention are advised to view MDC on a desktop or laptop device 
because the present version of MDC is not mobile friendly. The randomization 
sequence will be generated by the research team biostatistician using a permuted block 
randomization scheme stratified by clinic site and participants’ age group (age 65 and 
over vs under 65).   The randomized assignment for eligible participants will be 
accessible to the study coordinator and biostatistician using the Research Electronic 
Data Capture (REDCap™) Randomization Module. Once a randomization assignment 
is provided, the participant will be entered into the study and will be included in an 
intention to treat analysis in accordance with the CONSORT guidelines. Our target 
enrollment is 300 participants (150 per arm).  
 
5.0 
Study Procedures 
Setting. Participants will be recruited from 14 VUMC-affiliate adult primary care clinics 
located throughout Middle Tennessee (4 urban, 10 suburban). An EHR (Epic Systems 
Corp.) stores all clinical data and patients receive access to their clinical data via an 
integrated and highly-adopted patient web portal, MHAV. 
 
Participants and Recruitment. On a rolling basis, potentially eligible patients will be 
selected from a randomly ordered list of established adult patients with diabetes from 
participating clinic sites and sent a recruitment letter describing the study. In addition, 
we will use My Research at Vanderbilt to send the recruitment letter to current patient 
portal users who elected to allow investigators to contact them about research 
opportunities via email. Interested patients can contact a research assistant to learn 
more about the study. To enroll, participants will complete a web-based study eligibility 
screener and electronic consent form on the web via REDCap (Research Electronic 
Data Capture) version 5.0.8. 
 

 
 
Intervention and Control. Participants randomized to the intervention arm will be 
provided access to a version of MHAV embedded with the MDC viewable on a desktop 
or laptop device (MDC is not currently available on mobile devices).  MDC includes 
infographics to visualize and summarize patients' health data, incorporates motivational 
strategies (e.g., social comparisons and gamification), provides literacy-level 
appropriate educational resources, and contains secure-messaging capability. 
Participants randomized to the usual care arm will have access to the currently 
available version of MHAV that includes the ability for patients to review pertinent health 
data, review medical information about their conditions, and communicate with their 
health care team. 
 
Data Collection and Outcome Measures. Study participants will complete 
questionnaires electronically via email using REDCap™ at three time points:  enrollment 
(T0), three-month follow-up (T1), and six-month follow-up (T2). Enrolled participants will 
be asked to provide information on the following covariates: socioeconomic status, 
marital status, race/ethnicity, education level, and health literacy.  
 
The primary outcome measure will be change in patient activation as assessed by the 
Patient Activation Measure (PAM-13). Secondary intermediate outcomes include 
diabetes self-efficacy, diabetes knowledge, diabetes distress, diabetes self-care, system 
usability/satisfaction, and system usage. Additional secondary outcome such as blood 
glucose control, blood pressure control, cholesterol control, and flu vaccination status 
will also be assessed by EHR abstraction. To ensure the fidelity of the intervention, 
monthly quality assurance checks will be used to ensure the MDC is functioning 
correctly (e.g., displaying data correctly).  
 
Based on pilot testing, we estimate time to completion for questionnaires to be about 25 
minutes at T0 and about 20 minutes at T1 and T2. Participants will be compensated $40 
for completing the enrollment questionnaire (T0) and $35 each for completing the three-
month (T1) and six-month (T2) follow-up questionnaires.  
 
6.0  
Statistical Analysis Plan 
The study is designed to evaluate the effects of MDC on patient activation (primary 
analysis) and explore the effects on other secondary cognitive and behavioral outcomes 
relative to the control group. We will use a t-test to compare the change in PAM score 
between the MDC and control groups. If the normality assumption is violated, the non-
parametric Wilcoxon rank sum test will be used. We will use mixed-effects regression 
models to estimate the intervention effects across time while adjusting for the baseline 
measure of the outcome. Nonlinear associations will be modeled with regression 
splines. The mixed-effects model will use fixed effects for patient-level characteristics 
and random effects for health care provider variables. We will provide point estimates 
with CIs and graphically depict our results. If necessary, multiple imputation will be used 
to impute the missing values. The analysis with multiple imputation assumes missing at 
random (i.e., the model properly handles missing data by including covariates 
associated with reasons for dropout). The characteristics of participants who do not 
complete the study or do not comply with the treatment will be compared for both 

 
 
conditions. Independent t-tests or if appropriate, Wilcoxon rank sum tests will be used to 
compare change in secondary outcomes between the MCD and control groups.  Mixed-
effect models will also be used to evaluate the effects of MDC on secondary outcomes 
across time.