Table 1.

Effectiveness of SDT in diabetes self-management among adults.

Author	Year	Study title	Country	Population	Study design	Sample size	Sampling strategy	Summary findings
Murphy et al.	2015	A qualitative study of the experiences of care and motivation for effective self-management among diabetic and hypertensive patients attending public sector primary health care services in South Africa	South Africa	Hypertensive and diabetic patients 18 years and above.	Qualitative study comprising individual, in-depth interviews with hypertensive and diabetic patients	22	A criterion sampling procedure was used to select patients who had diabetes and/or hypertension	Patients experience multiple impediments to effective self-management of diabetes and behaviour change, including poor health literacy, a lack of self-efficacy, and perceived social support. Most patients reported not having received adequate information, counselling, or autonomy support from their healthcare providers. Their experiences suggest that the current approach to chronic care largely fails to meet patients' motivation needs, leaving many of them feeling anxious about their state of health and frustrated with the quality of their care.
De Man et al.	2020	What motivates people with (pre)diabetes to move? Testing SDT in rural Uganda	Uganda	Adults aged 30-75 years in two rural districts in eastern Uganda	The study was a cluster-randomized adaptive implementation trial	794	Cluster sampling technique	Their findings suggest that different types of motivation regulate different domains and intensities of PA. A higher frequency of vigorous PA—which was linked to a lower HbA1C and FPG—was predicted by autonomous motivation but not by controlled motivation. Perceived competence and perceived relatedness predicted autonomous motivation. Autonomous motivation functioned as a mediator between those needs and PA behaviour.
Karlsen et al.	2018	New possibilities in life with type 2 diabetes: experiences from participating in a guided self-determination program in general practice	Norway	Adults with type 2 diabetes mellitus	Descriptive and explorative qualitative approach	16	Purposive and convenient sampling technique	The findings indicate that the participants experienced new life possibilities after participating in the SDT program, which positively influenced their motivation for self-management. Through reflections on how to live with diabetes, the participants reinterpreted their life with diabetes by gradually developing a closer relationship with the disease and moving towards acceptance. Dialogue with nurses was seen to have helped support the participants to become more self-determined.
Liu et al.	2018	Effectiveness of self-management behaviour intervention on type 2 diabetes based on SDT	China	Adult diabetic patients in 3 selected communities in Beijing	Pretest posttest intervention study	3 communities	Convenient sampling method	The HbA1c and self-management scores increased higher in the autonomy support group than in the other two groups. After the intervention, the control rate in the autonomy support group was higher than in the other two groups. The value in the autonomy support group was higher than in the routine intervention group. Baseline self-management behaviour, self-efficacy, knowledge, skill, family support, autonomy support, peer support, and age were positively correlated with the change in behaviour.
Gourlan et al.	2016	Motivational profiles for physical activity practice in adults with type 2 diabetes: an SDT perspective	France	Adult type 2 diabetics patients in a diabetes care Centre in a French hospital	Cross-sectional design	350	—	Participants with “high combined” and “self-determined” profiles reported higher perceived competence and longer leisure-time PA practice in comparison to those with a “moderate” profile. This study highlights the necessity of adopting a person-centred approach better to understand motivation towards PA among type 2 diabetes patients.
Sebire et al.	2018	“I've made this my lifestyle now”: a prospective qualitative study of motivation for lifestyle change among people with newly diagnosed type two diabetes mellitus	England	Newly diagnosed adults with type 2 diabetes and were participants in the early ACTID trial	Randomized control trial	593	Purposive sampling	Applying SDT, it was found that many participants reported relatively dominant controlled motivation to comply with lifestyle recommendations, avoid their non-compliance being “found out” or suppress guilt following lapses in behaviour change attempts. Such narratives were accompanied by experiences of frustrating slow behaviour change progress. More autonomous motivation was expressed as something often achieved over time and reflected goals to improve health, QoL, or family time.
Rajab et al.	2020	Barriers to initiation of insulin therapy in poorly controlled type 2 diabetes based on self-determination theory	Iran	Patients with type 2 diabetes who had indications for insulin therapy	Descriptive cross-sectional study	151	Random sampling	The findings suggested that the patient's intrinsic motivation was less than their extrinsic motivation. It was observed that patients do not properly understand their illness due to the low score of relatedness representative of patients' and care providers' relationships.
Halvari et al.	2017	Physical activity and motivational predictors of changes in health behavior and health among DM2 and CAD patients	Norway	Adult patients with both type 2 diabetes and coronary artery disease (CAD)	Clinical trial	108	Purposive sampling	The data supported the SDT process model, in which the effect of the intervention significantly predicted indirect changes in behaviour and health through motivation variables. Considering the moderate to large effects on increases in motivation, behaviour, and health, promoting organized physical activity programs that are perceived as need-supportive may have important health implications for patients with DM2 and CAD.
Yun et al.	2020	Can autonomy support have an effect on type 2 diabetes glycemic control? Results of a cluster randomized controlled trial	China	Patients with type 2 diabetes	Cluster randomized controlled trial	364	Purposive and convenient sampling	Patients in an autonomous support group (ASP) achieved better HbA1c reduction at the end of intervention than those in the usual care group (UCG) and successfully maintained it for up to 6 months. However, patients in a social support group (SSG) did not experience a significant change in HbA1c at 3 or 6 months when compared with patients in UCG. Besides, patients in both the SSG and ASG experienced an improvement in exercise at 3 months. Patients in ASG sustained improvement in exercise for up to 6 months but those in the SSG did not. Autonomy support for patients with type 2 diabetes could help achieve glycaemic control at the end of the intervention and successfully maintain it for up to 6 months.
Nouwen et al.	2011	Longitudinal motivational predictors of dietary self-care and diabetes control in adults with newly diagnosed type 2 diabetes mellitus	Netherlands	People newly diagnosed with type 2 diabetes	Longitudinal study design	237	Purposive sampling	Dietary self-care was longitudinally associated with self-efficacy, self-evaluation, autonomy support, and autonomous motivation. The results indicate that autonomy support, self-efficacy, and self-evaluation are key targets for interventions to improve dietary self-care.
Koponen et al.	2018	Success in increasing physical activity (PA) among patients with type 2 diabetes: a self-determination theory perspective	Finland	Patients with type 2 diabetes	Cross-sectional survey	1256	—	The findings of this study supported SDT by showing that autonomous motivation was the strongest predictor of success in increasing PA among people with type 2 diabetes. The autonomous motivation was associated with success in increasing PA even after the effect of other important life-context factors was controlled for.
Koponen et al.	2017a	Determinants of physical activity among patients with type 2 diabetes: the role of perceived autonomy support, autonomous motivation, and self-care competence	Finland	Patients with type 2 diabetes	Cross-sectional survey	5167	Purposive sampling	Of all measured explanatory factors, autonomous motivation was most strongly associated with engagement in PA. Autonomous motivation mediated the effect of perceived autonomy support on patients' PA. Thus, perceived autonomy support was associated with the patient's PA through autonomous motivation. Interventions for improved diabetes care should concentrate on supporting patients' autonomous motivation for PA. Internalizing the importance of good self-care seems to give sufficient energy to maintain a physically active lifestyle.
Koponen et al.	2017b	Quality of primary health care and autonomous motivation for effective diabetes self-management among patients with type 2 diabetes	Finland	Patients with type 2 diabetes	Cross-sectional survey	2866	Purposive sampling	Autonomy support from one's physician was most strongly associated with autonomous motivation (self-regulation) for effective diabetes self-management among patients with type 2 diabetes.
Mohn et al.	2017	The effect of guided self-determination on self-management in persons with type 1 diabetes mellitus and HbA1c ≥64 mmol/Mol: a group-based randomized controlled trial	Western Norway	Adults (all Caucasian) aged 18–55 with type 1 DM for at least 1 year and HbA1c ≥64 mmol/Mol	Prospective randomize control trial	178	Random assignment	Participants in the guided self-determination group training (GSD-GT) group exhibited a significant reduction in diabetes-related distress relative to the control group (CG) the GSD-GT group showed an increase in self-esteem relative to the CG.
Güil Oumrait et al.	2020	Can self-determination explain dietary patterns among adults at risk of or with type 2 diabetes? A cross-sectional study in socioeconomically disadvantaged areas in Stockholm	Sweden	Adults at risk of and with type 2 diabetes from two socioeconomically disadvantaged Stockholm areas	Quantitative cross-sectional design	147	Purposive sampling	Two dietary patterns (healthy and unhealthy) were identified. The competence construct was most strongly associated with a healthy diet. Autonomous motivation and competence mediated the effect of relatedness on diet behaviour. In conclusion, social surroundings can promote adults at high risk of or with type 2 diabetes to sustain healthy diets by supporting their autonomous motivation and competence.