Background
Description of the interventions
How the interventions might work
Why is it important to do this systematic review
Ng et al. [40] | Gillison et al. [21] | Ntoumanis et al. [20] | |
---|---|---|---|
Designs included | 184 independent datasets, primarily non-experimental design | 74 studies including a control group (59 of randomised clinical trials (RCTs) or cluster RCTs) | 73 independent datasets, 58 RCTs (20 of these were cluster RCTs) |
Number of trials including people with diabetes | One trial [47] | ||
Registered in PROSPERO | No | No | No |
Protocol published | No | No | No |
Restricted searches | PsycINFO, PsycARTICLES and PubMed, citation searches (ISI web of knowledge) | Web of Science, PsychINFO, PubMed, Cochrane Database, DARE, Biomed Central, Sociological abstracts, ProQuest | PsycINFO, PsycARTICLES and PubMed/Medline |
Assessment of bias risk | Not performed | A modified version of the Cochrane risk of bias tool (random group allocation, treatment allocation concealment, groups similar at baseline, blinded outcome assessor, intention-to-treat analyses, risk of bias) | A modified version of the Cochrane risk of bias tool (random group allocation, group allocation concealment, blinded outcome assessor, handling of missing data, selective reporting, other bias) |
Assessment of random errors, using trial sequential analysis | No | No | No |
Outcomes | Specific self-determination theory constructs | Specific self-determination theory constructs | Specific self-determination theory constructs |
Assessment of adverse effects | No | No | No |
Objective
Methods
Criteria for considering studies for this review
Types of studies
Types of participants
Types of interventions
Control group interventions
Outcomes
Primary outcomes
-
All-cause mortality (dichotomous data).
-
Proportion of participants with one or more serious adverse events (dichotomous data), defined as any untoward medical occurrence that resulted in death, was life-threatening, required hospitalisation or prolonging of existing hospitalisation and resulted in persistent or significant disability or jeopardised the patient [60]. If the trialists do not use the ICH-GCP definition, we will include the data if the trialists use the term “serious adverse event.” If the trialists do not use the ICH-GCP definition nor use the term serious adverse event, then we will also include the data, if the event clearly fulfils the ICH-GCP definition for a serious adverse event.
Secondary outcomes
-
Proportion of participants with at least one adverse event (dichotomous data) not considered serious [60].
Explorative outcomes
-
HbA1c (continuous data).
-
Motivation measured by the 21-items Treatment Self-Regulation Questionnaire (TSRQ) consists of three subscales measuring the patient’s reasons for taking diabetes medication, checking glucoses, following diet and exercising regularly: (I) autonomous, originating from the self, (II) controlled, pressured or coerced by intrapsychic or interpersonal forces or (III) a-motivated, without intention to change and often feeling unable to change (continuous data).
Assessment time points
Search methods for identification of studies
Electronic searches
Searching other resources
-
Google Scholar (https://scholar.google.dk/)
-
The Turning Research into Practice (TRIP) Database (https://www.tripdatabase.com/)
-
European Medicines Agency (EMA) (http://www.ema.europa.eu/ema/)
-
US Food and Drug Administration (FDA) (www.fda.gov)
-
China Food and Drug Administration (CFDA) (http://eng.cfda.gov.cn/WS03/CL0755/)
-
Medicines and Healthcare Products Regulatory Agency (https://www.gov.uk/government/organisations/medicines-and-healthcare-products-regulatoryagency)
-
The World Health Organisation (WHO) International
-
Clinical Trials Registry Platform (ICTRP) search portal (http://apps.who.int/trialsearch/)
-
Cochrane Database of Systematic Reviews
Data collection and analysis
Selection of studies
Data extraction and management
Trial characteristics
Participants characteristics and diagnosis
Intervention group
Education and training of the interventionists
Co-intervention characteristics
Control group intervention
Outcomes
Notes
Risk of bias assessment
Random sequence generation
-
Low risk of bias: study authors performed sequence generation using computer random number generation or a random numbers table. Drawing lots, tossing a coin, shuffling cards, and throwing dice were adequate if an independent person not otherwise involved in the study performed them.
-
Unclear risk of bias: study authors did not specify the method of sequence generation.
-
High risk of bias: sequence generation method was not random or quasi-randomised. Such studies will be excluded for the assessment of benefits.
Allocation concealment
-
Low risk of bias: participant allocations could not have been foreseen in advance of, or during, enrolment. A central and independent randomisation unit controlled the allocation. Investigators were unaware of the allocation sequence (e.g. if the allocation sequence was hidden in sequentially numbered, opaque and sealed envelopes)
-
Unclear risk of bias: study authors did not describe the method used to conceal the allocation, so intervention allocations may have been foreseen before, or during, enrolment
-
High risk of bias: it is likely that investigators who assigned participants knew the allocation sequence
Blinding of participants and personnel
-
Low risk of bias: either of the following: no blinding or incomplete blinding, but review authors judged that the outcome was unlikely to have been influenced by lack of blinding or blinding of participants and key study personnel ensured, and it was unlikely that the blinding could have been broken
-
Unclear risk of bias: either of the following: insufficient information to permit judgement of ‘low risk’ or ‘high risk’; or the trial did not address this outcome
-
High risk of bias: either of the following: no blinding or incomplete blinding, and the outcome was likely to have been influenced by lack of blinding; or blinding of key study participants and personnel attempted, but likely that the blinding could have been broken, and the outcome was likely to have been influenced by lack of blinding
Blinding of outcome assessment
-
Low risk of bias: either of the following: no blinding of outcome assessment, but review authors judged that the outcome measurement was not likely to be influenced by lack of blinding (we will consider self-reported questionnaires more prone to be affected by lack of blinded outcome assessor and hba1c less likely to be affected by lack of blinded outcome assessor) or blinding of outcome assessment ensured, and unlikely that the blinding could have been broken.
-
Unclear risk of bias: either of the following: insufficient information to permit judgement of ‘low risk’ or ‘high risk’; or the trial did not address this outcome.
-
High risk of bias: either of the following: no blinding of outcome assessment, and the outcome measurement was likely to be influenced by lack of blinding; or blinding of outcome assessment, but likely that the blinding could have been broken, and the outcome measurement was likely to be influenced by lack of blinding.
Incomplete outcome data
-
Low risk of bias: missing data were unlikely to make treatment effects depart from plausible values. The study used adequate methods, such as multiple imputation, to handle missing data or had < 5% missing data.
-
Unclear risk of bias: information was insufficient to assess whether missing data in combination with the method used to handle missing data were likely to induce bias on the results.
-
High risk of bias: results were likely to be biassed due to missing data.
Selective outcome reporting
-
Low risk of bias: a protocol is published, or a trial has been registered in a trial register (e.g. clinicaltrials.gov) before or at the time the trial is begun, and the outcome called for in the protocol or trial registration is reported on.
-
Unclear risk of bias: study authors did not report all pre-defined outcomes fully, or it was unclear whether study authors recorded data on these outcomes.
-
High risk of bias: study authors did not report one or more pre-defined outcomes.
Other bias
-
Low risk of bias: the trial appeared free of other factors that could have put it at risk of bias
-
Unclear risk of bias: the trial may or may not have been free of other factors that could have put it at risk of bias
-
High risk of bias: other factors in the trial could have put it at risk of bias