The process of rehabilitation is often long and challenging, requiring active participation from the care team and the patient. Patient participation, however, is often lacking in rehabilitation settings.1-3 Some of the most common reasons for patients’ lack of participation and adherence to treatment are poor communication with providers, complex treatment regimens, cost, and access barriers.1,4 A lack of motivation has also been cited as a common reason for low adherence.1 In a general sense, adherence is how closely and how often a patient follows the treatment plan recommended by their care team. The World Health Organization defines adherence as “the extent to which a person’s behavior…corresponds with agreed recommendations from a healthcare provider.”1 Increased adherence has been linked to positive outcomes, including patient satisfaction, function, quality of life, and long-term overall health-related costs.1,5
Psychological and educational interventions have been shown to increase adherence in several patient populations.6-7 Some of these interventions, however, have not been derived from an established psychological framework, and their implications are therefore limited to the specific intervention the study authors designed and the population treated in that study. This article is based on a review completed by the authors as part of the capstone research project at the Northwestern University Prosthetics-Orthotics Center. The aim was to determine the effect of self-determination theory (SDT)–based interventions on O&P patients’ motivation and adherence to prescribed treatment programs. Understanding these concepts can provide clinicians with meaningful perspectives and tools to improve clinical care.
Self-Determination Theory
SDT is a macro theory of human behavior consisting of six mini theories used to explain motivation scale and the basic psychological needs of autonomy, competence, and relatedness.8 When combined, these theories describe the motivation continuum from amotivation (no participation) to intrinsic motivation (full participation). Basic psychological needs theory posits that when an individual’s basic psychological needs of autonomy, competence, and relatedness are fulfilled, the individual will be intrinsically motivated. Conversely, when one or more of these basic psychological needs is unfulfilled, the individual will tend to move toward a state of amotivation.8 These concepts have been widely accepted in psychology and have since been adopted by many health disciplines because of their potential to enhance and improve patient/client rehabilitation outcomes.9-12
In their work developing SDT, Ryan and Deci defined relatedness as meaningful connection to others. Further, they emphasized that despite the salient contributions autonomy and competence make, incorporation of a new and healthy sense of relatedness may make the greatest contribution to motivation. Ryan and Deci also discussed the connection between, autonomy, competency, and self-efficacy.8 Given this, it is helpful to think of SDT as a two-pronged way of understanding and improving patient motivation, and combining self-efficacy with relatedness shows the greatest potential for improving an individual’s intrinsic motivation.13-14
Literature Review
The PubMed, CINAHL, and PsycINFO databases were searched to identify articles focusing on SDT-based interventions designed to increase adherence to treatment plans in the context of rehabilitative medicine. Eight articles met the inclusion criteria and were included in the review.
Study Participants
The number of participants in each study ranged from ten to 450, with the mean number of participants being 118. The sample size in most studies was less than 100 (n=5) with only one having a sample size over 400. In the articles that mentioned age (n=6), participants had an average age of 55.1 years. Participants in the studies had a range of health conditions. The most common were spinal cord injury (n=2) and arthritis (n=2). One article included participants with multiple health conditions. The breakdown of these conditions can be seen in Figure 2.
Interventions
In each of these studies, patients participated in an intervention designed to increase adherence to their prescribed treatment plans. Each intervention was distinct, however several focused on the same delivery method. These delivery methods included planned meetings with counselors or clinicians (n=5), unplanned clinical interactions with clinicians (n=2), standardized and predetermined programs delivered remotely (n=2), and peer support (n=2). The interventions are described in Figure 3. Some of the interventions included more than one implementation method (n=2).15,19 These interventions were all based in SDT either through SDT-based programming (such as education modules and worksheets) (n=5) and/or interaction with SDT-trained clinicians (n=7).
Defining and Assessing Adherence
Most of the studies defined adherence using a ratio of completed treatment compared to prescribed treatment,15-19,22 though some defined it as participation in over 75 percent of prescribed exercise sessions20 or using a seven-point rating scale from “completed none” to “completed all.”21 In the reviewed studies, adherence was assessed in different ways, including monitoring relevant changes in patient condition (n=2), direct monitoring of patient adherence through methods such as accelerometer wear and app data collection (n=3), self-report measures (n=6), clinician-reported adherence (n=1), and independent rater–reported adherence (n=1). Multiple articles used more than one adherence measure with some studies using two measures (n=3) and two studies using three measures. Figure 4 describes the adherence measures implemented in the reviewed studies.
Impact of Intervention on Adherence
Of the eight articles, six showed improvement in adherence to treatment plans compared to control groups (n=3) or typical/preintervention treatment outcomes (n=3). The remaining two articles found no noticeable changes in patient adherence compared to control groups. Notably, the two studies without significant findings measured adherence directly through either a tracking device or logged sessions. Of the studies that found improvement in adherence compared to control groups, the average adherence increase was described using different methods, making it difficult to directly compare the results. The articles found that SDT had a large effect on, significantly mediated the results, or significantly positively predicted changes in adherence to the prescribed treatment plans. These results demonstrate that these adherence measures changed due to the SDT interventions, not random chance.
Discussion
Because each of the eight studies focused on different interventions, patient populations, and adherence measures, caution must be exercised when drawing conclusions regarding the impact of SDT on adherence. Additionally, while the studies addressed conditions commonly seen in O&P care, none of them investigated specific O&P interventions. Despite this, there are some notable trends in the literature that can inform O&P care. It appears that SDT-based interventions have an overall positive impact on adherence. Six of the eight articles showed improved treatment plan adherence in SDT intervention groups compared to nonintervention groups. While certainly not conclusive, when combined with available evidence for the impact of SDT on patient outcomes, this research is sufficient to warrant further experimentation and implementation of these types of interventions.
The most common interventions included planned interactions with SDT-trained clinicians or counselors. The explicit nature of these interventions may have had an impact on the results of the studies. (If participants are aware that they are in a study, they are more likely to behave differently than if they are unaware.23) This contrasts with O&P clinical care, where patients are relatively unaware of the training clinicians have undergone. In only one of the studies were patients unaware of the practitioner training having taken place, and this article showed improvements in adherence.21 Another notable feature is the remote delivery method of many interventions. Half of the reviewed articles included telehealth aspects within their intervention and this increased the flexibility of some of the interventions.16,17,19,20 This may have played a role in the adoption of greater adherence as well, as one of the tenets of SDT states that allowing individuals greater autonomy increases intrinsic motivation.8
Clinical Implications
The reviewed literature suggests that SDT may provide a helpful framework for improving patient adherence by equipping clinicians to understand why patients are choosing not to participate as a partner in their treatments. Understanding the “whys” of adherence may help clinicians personalize care for each patient. Further, as practitioners adapt to providing clinical care in a postpandemic world, providing telehealth services/interventions may provide an opportunity to affect adherence without requiring an in-person visit. Many patients with limited mobility would benefit from this type of care.
When providing O&P interventions intended to improve mobility, use of the device is both a desired outcome and part of treatment. For example, participation in physical therapy sessions provides essential training in the proper use of a prosthesis and supports the development of the physical and physiological abilities necessary to maintain function and forestall physical decline. Practitioners recognize the importance of patients making meaningful connections with others who have successfully navigated similar challenges, and the need for patients to recognize how use of the device can improve their effectiveness in dealing with everyday life. The need for autonomy, and how our interactions with patients can support or limit it, is less understood.
The term “compliance” can communicate that patients are simply responsible to follow our orders. “Adherence” more accurately captures the idea of a partnership between patients and clinicians, with patients responsible to adhere to a treatment plan designed in collaboration with a clinician. Actively working to engage patients, include them in decisions, improve their ability to form and maintain meaningful relationships, and maximize their functional independence all make a significant contribution to their well-being.
Sean Herrin, MPO; Chris Koch, MPO; and Nathan Dunfee, MPO, are 2024 graduates of the Masters of Prosthetics & Orthotics program at Northwestern University Prosthetics-Orthotics Center and are currently completing residency training. They wish to acknowledge John Brinkmann, CPO, for his support of this project.
Academy Society Spotlight is a presentation of clinical content by the Scientific Societies of the Academy in partnership with The O&P EDGE.
References
Chaudri, N. A. 2003. Adherence to long-term therapies evidence for Action World Health Organization (WHO). [English]. 2004. Annals of Saudi Medicine 24(3):221–2.
Sriramulu, S. B., A. R. Elangovan, M. Isaac, and J. R. Kalyanasundaram. 2021. Treatment non-adherence pattern among persons with neuropsychiatric disorders: A study from a Rural Community Mental Health Centre in India. International Journal of Social Psychiatry 68(4):844–51.
