A Proof-of-Concept Study Evaluating a Theory-Based Motivational Letter to Increase Attendance to a One-Year Post-Cardiac Rehabilitation Risk Factor Check
Phase: NA
Conditions: Cardiovascular Diseases (CVD)
Sponsor: University of Calgary

 
 
 
 
 
Cover Page for ClinicalTrials.gov 
 
Document: 
Study Protocol 
 
Official Study Title: 
A proof-of-concept study evaluating a theory-based motivational letter to increase attendance to 
a one-year post-cardiac rehabilitation risk factor check 
 
Document Date: 
January 26, 2024 
 
 
 
 
 
 
 
 
 

Ethics ID: REB23-1586 
Study Title: A proof-of-concept study evaluating a theory-based motivational letter to support maintenance 
of health practices following cardiac rehabilitation 
PI: Tavis Campbell  
Version 1.1: January 26, 2024 
Title: A proof-of-concept study evaluating a theory-based motivational letter to increase 
attendance to a one-year post-cardiac rehabilitation risk factor check 
Background. Cardiovascular diseases (CVD) are among the leading causes of mortality 
worldwide1. Cardiac rehabilitation (CR) can improve medical and psychological outcomes for 
patients with CVD2. Patient follow-up appointments in the months and years following CR may 
support long-term medication management and maintenance of health behaviours (i.e., 
adherence to exercise regimen, dietary recommendations, smoking cessation)3. Despite the 
importance of long-term follow-up, unpublished internal data from TotalCardiology 
Rehabilitation (TCR) indicates that ~20-30% of patients do not attend these visits. Suboptimal 
attendance at one-year post-CR appointments may be influenced by 1) a patient lack of 
awareness, 2) patient perceptions of the appointment as unnecessary, 3) practical or scheduling 
issues, 4) comorbid health concerns and 5) anticipated unpleasant experiences at the 
appointment4. The use of motivational theory may be particularly useful for improving patient 
attendance at one-year post-CR appointments5. Previous studies have demonstrated low-cost 
letters based on theories of behaviour change can improve initial CR attendance, but this 
approach has not been tested in the context of follow-up care after CR. The theory of planned 
behaviour (TPB)6 and health action process approach (HAPA) represent psychological 
frameworks which posits that intention to engage in a behaviour (e.g. appointment attendance) is 
influenced by an individual's attitudes about a behaviour, perceived control over the behaviour, 
and subjective norms associated with performing the behaviour. TPB and HAPA may inform 
cost-effective written communications to improve maintain exercise and other health practices 
following CR. 
Current study. This presents the ideal opportunity for an evidence- and theory-driven approach to 
promote cardiac patient attendance at one-year post-CR follow-up appointments. The current 
study will evaluate the impact of a letter rooted in the TPB6, HAPA, and based on earlier 
qualitative work on barriers to TCR one-year appointment attendance4, mailed out to patients 6 
months in advance of their one-year post-CR follow-up appointment. This study is also guided 
by the ORBIT model,7 which recommends the use of theory and early-phase qualitative research 
to optimize the design and efficacy of behaviour change interventions. 
Objectives. The proposed project aims to evaluate the influence of a motivational reminder letter 
on patients’ one-year post-CR appointment attendance. Primary objective. To assess whether a 
theory-based reminder letter increases patient attendance at a one-year follow-up compared to 
patients who receive their care as usual. Secondary objectives. a) To assess whether a theory-
based reminder letter improves risk factor control (e.g., cardiorespiratory fitness, lipid control) 
compared to usual care; b) To assess demographic and clinical and risk factor variables 
associated with attendance of the one-year post-CR appointment; c) To describe trajectories of 
risk factor changes following cardiac rehabilitation. Methods. Sample: Prospective participants 
will be recruited in person at their post-CR (12-week) appointment by TCR administrative staff.  
Inclusion criteria: Participants will be patients who: 1) have provided written consent to 
participate, 2) attended their 12-week post-CR visit, 3) program status not listed as “discharged” 
or “deceased,” and 4) have a pre-booked 1-year visit marked in their patient chart. Study design: 
Eligible participants who have consented to participate will be randomly assigned to either 

Ethics ID: REB23-1586 
Study Title: A proof-of-concept study evaluating a theory-based motivational letter to support maintenance 
of health practices following cardiac rehabilitation 
PI: Tavis Campbell  
Version 1.1: January 26, 2024 
receive the motivational letter reminder, or care as usual. Theory-based letters will be mailed 
directly to participants’ home addresses at approximately 6-months post-CR (i.e. 6-months 
before their scheduled one-year appointment). Outcome measures. Primary outcome. Attendance 
at the one-year follow-up appointment (assessed by a binary, yes or no). Secondary outcomes. 
Demographics, clinical characteristics, and risk factors will be collected as part of standard care 
at TCR, then collected by researchers via TCR medical chart review. 
Analytic plan: Assuming 80% power, an alpha of 0.05, assuming 90% of patients in the 
intervention group attend their 1-year follow up, and a 5% attrition rate (i.e., due to death, or 
program drop out), approximately 102 participants (51 participants per group with complete 
data) will be recruited to participate in this study. The primary outcome will be evaluated using 
chi-square and descriptive statistics. Secondary outcomes will be assessed using descriptives and 
t-tests. 
Implications. Demonstrating a clinically significant increase in post-CR follow-up attendance 
will be important for optimizing patient attendance and translating findings into standard practice 
at TotalCardiology. If the letter is shown to increase attendance, it would represent a low-cost 
way to increase uptake to follow-up care after CR. This study will provide important data on 
maintenance of risk factor control after CR. 
 
 

Ethics ID: REB23-1586 
Study Title: A proof-of-concept study evaluating a theory-based motivational letter to support maintenance 
of health practices following cardiac rehabilitation 
PI: Tavis Campbell  
Version 1.1: January 26, 2024 
References 
1. World Health Organization (WHO), 2023. Retrieved from https://www.who.int/health-
topics/cardiovascular-diseases#tab=tab_1 
 
2. Bellmann, B., Lin, T., Greissinger, K., Rottner, L., Rillig, A., & Zimmerling, S. (2020). 
The beneficial effects of cardiac rehabilitation. Cardiology and therapy, 9(1), 35-44. 
3. Bellmann, B., Lin, T., Greissinger, K., Rottner, L., Rillig, A., & Zimmerling, S. (2020). 
The beneficial effects of cardiac rehabilitation. Cardiology and therapy, 9(1), 35-44. 
4. Giannoccaro, J. D., Aggarwal, S., Grace, S. L., Campbell, T. S., Hauer, T., Arena, R., & 
Rouleau, C. R. (2020). Factors Associated with Attendance at a 1-yr Post–Cardiac 
Rehabilitation Risk Factor Check. Journal of Cardiopulmonary Rehabilitation and 
Prevention, 40(3), E22-E25. 
5. Mosleh, S. M., Bond, C. M., Lee, A. J., Kiger, A., & Campbell, N. C. (2014). 
Effectiveness of theory-based invitations to improve attendance at cardiac rehabilitation: 
A randomized controlled trial. European journal of cardiovascular nursing, 13(3), 201-
210. 
6. Ajzen, I. (1991). The theory of planned behavior. Organizational behavior and human 
decision processes, 50(2), 179-211. 
7. Czajkowski, S. M., Powell, L. H., Adler, N., Naar-King, S., Reynolds, K. D., Hunter, C. 
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Whooley MA, Chang T, Stolp H, Schieb L, Wright J. Tracking Cardiac Rehabilitation 
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National Initiative. Circ Cardiovasc Qual Outcomes. 2020 Jan;13(1):e005902. doi: 
10.1161/CIRCOUTCOMES.119.005902. Epub 2020 Jan 14. PMID: 31931615; PMCID: 
PMC8091573.