Efficacy and safety of n-3 fatty acids supplementation on depression: a systematic review and dose-response meta-analysis of randomised controlled trials

We aimed to investigate the effectiveness of n-3 fatty acids supplementation on the risk of developing depression, depressive symptoms and remission of depression. We searched PubMed, Scopus and Web of Science from inception to December 2022 to find randomised trials of n-3 fatty acids supplementation in adults. We conducted random-effects meta-analyses to estimate standardised mean differences (SMD) and 95 % CI for continuous outcomes and risk difference and 95 % CI for binary outcomes. A total of sixty-seven trials were included. Each 1 g/d n-3 fatty acids supplementation significantly improved depressive symptoms in adults with and without depression (moderate-certainty evidence), with a larger improvement in patients with existing depression. Dose-response analyses indicated a U-shaped effect in patients with existing depression, with the greatest improvement at 1·5 g/d. The analysis showed that n-3 fatty acid supplementation significantly increased depression remission by 19 more per 100 in patients with depression (low-certainty evidence). Supplementation with n-3 fatty acids did not reduce the risk of developing depression among the general population, but it did improve the severity of depression among patients with existing depression.

A systematic review and meta-analysis of the long-term effects of physical activity interventions on objectively measured outcomes

BACKGROUND

Although physical activity interventions are frequently reported to be effective, long-term changes are needed to generate meaningful health benefits. There are criticisms that evaluations of physical activity interventions mostly report short-term outcomes and that these are often self-reported rather than measured objectively. This study therefore aimed to assess the long-term (at least 24 month) effectiveness of behavioural interventions on objectively measured physical activity.

METHODS

We conducted a systematic review with a meta-analysis of effects on objectively measured physical activity. We searched: Cochrane CENTRAL, EMBASE, PsychInfo, CINAHL and Pubmed up to 10th January 2022. Studies were included if they were in English and included a physical intervention that assessed physical activity in the long-term (defined as at least 24 months).

RESULTS

Eight studies with 8480 participants were identified with data suitable for meta-analysis. There was a significant effect of interventions on daily steps 24 months post baseline (four studies, SMD: 0.15, 95% CI: 0.02 to 0.28) with similar results at 36 to 48 months of follow up (four studies, SMD: 0.17, 95% CI: 0.07 to 0.27). There was a significant effect of interventions on moderate-to-vigorous physical activity 24 months post baseline (four studies, SMD: 0.18 95% CI: 0.07 to 0.29) and at 36 to 48 months (three studies, SMD: 0.16 95% CI: 0.09 to 0.23). The mean effect size was small. However, the changes in moderate-to-vigorous physical activity and steps per day were clinically meaningful in the best-performing studies.

CONCLUSION

This review suggests that behavioural interventions can be effective in promoting small, but clinically meaningful increases in objectively measured physical activity for up to 48 months. There is therefore a need to develop interventions that can achieve greater increases in long-term physical activity with greater efficiency.

Changes in technology acceptance among older people with dementia: the role of social robot engagement

OBJECTIVE

Emerging technologies such as social robots have shown to be effective in reducing loneliness and agitation for older people with dementia. However, the acceptance of technology (specifically social robots) was found to be low for older people with dementia. The current understanding of changes in technology acceptance following direct exposure is limited and lacks rigorous study design. This study examined the change in technology acceptance after a direct interaction with a humanoid social robot (Kabochan) that was deployed for long-term care facilities' residents with dementia.

METHODS

The technology acceptance was assessed using randomised control trials for a time frame of 32 weeks. A total of 103 residents clinically diagnosed with dementia, with a mean age of 87.2 years (SD = 7.4), were recruited from seven long-term care facilities in Hong Kong and were randomly allocated to either Kabochan-engagement group or control group. Participants in the engagement group interacted with Kabochan in an individual, non-facilitated approach. The behavioural engagement with Kabochan was observed by care workers and recorded into constructive engagement and non-engagement. Questionnaire surveys were taken placed at pre- and post-exposure with Kabochan to measure attitudes and beliefs towards technology. The questionnaire was based on previous studies on technology acceptance and included attitudes towards technology, perceived usefulness, perceived ease of use, technology self-efficacy, technology anxiety, and facilitating conditions.

RESULTS

Perceived ease of use was improved at week 32 for participants who interacted with Kabochan (F = 4.239, p = 0.042) with a small effect (η_p² = 0.043) in comparison to usual care group. Results further demonstrated that the magnitude of belief changes was related to the intensity of constructive behavioural engagement. Specifically, resident-robot behavioural engagement moderately improved attitudes towards technology (F = 11.62, p < 0.001, η_p² = 0.11) and perceived usefulness (F = 5.75, p = 0.02, η_p² = 0.06).

CONCLUSIONS

The study tentatively supports that exposure to Kabochan has potential for changing perceived ease of use but not for other beliefs and attitudes towards technology among long-term care residents with dementia. Direct engagement with a humanoid social robot might be promising in improving the perceived ease of use towards technology.

Changes to aspects of ongoing randomised controlled trials with fixed designs

Background

Despite careful planning, changes to some aspects of an ongoing randomised clinical trial (RCT), with a fixed design, may be warranted. We sought to elucidate the distinction between legitimate versus illegitimate changes to serve as a guide for less experienced clinical trialists and other stakeholders.

Methods

Using data from a large trial of statin therapy for secondary prevention, we generated a set of simulated trial datasets under the null hypothesis (H0) and a set under an alternative hypothesis (H1). Through analysis of these simulated trials, we assessed the performance of the strategy of changing aspects of the design/analysis with knowledge of treatment allocation (illegitimate) versus the strategy of making changes without knowledge of treatment allocation (legitimate). Performance was assessed using the type 1 error, as well as measures of absolute and relative bias in the treatment effect.

Results

Illegitimate changes led to a relative bias of 61% under H1, and a type 1 error rate under H0 of 23%—well in excess of the 5% significance level targeted. Legitimate changes produced unbiased estimates under H1 and did not inflate the type 1 error rate under H0.

Conclusions

Changes to pre-specified aspects of the design and analysis of an ongoing RCT may be a necessary response to unforeseen circumstances. Such changes risk introducing a bias if undertaken with knowledge of treatment allocation. Legitimate changes need to be adequately documented to provide assurance to all stakeholders of their validity.

Understanding usual care in randomised controlled trials of complex interventions: A multi-method approach

BACKGROUND

Evaluations of complex interventions compared to usual care provided in palliative care are increasing. Not describing usual care may affect the interpretation of an intervention's effectiveness, yet how it can be described remains unclear.

AIM

To demonstrate the feasibility of using multi-methods to describe usual care provided in randomised controlled trials (RCTs) of complex interventions, shown within a feasibility cluster RCT.

DESIGN

Multi-method approach comprising usual care questionnaires, baseline case note review and focus groups with ward staff completed at study end. Thematic analysis of qualitative data, descriptive statistics of quantitative data, followed by methodological triangulation to appraise approach in relation to study aim.

SETTING/PARTICIPANTS

Four general medical wards chosen from UK hospitals. Purposive sampling of healthcare professionals for usual care questionnaires, and focus groups. Review of 20 patients' notes from each ward who died during admission or within 100 days of discharge.

RESULTS

Twenty-three usual care questionnaires at baseline, two focus groups comprising 20 healthcare professionals and 80 case note reviews. Triangulation of findings resulted in understanding the usual care provided to the targeted population in terms of context, structures, processes and outcomes for patients, families and healthcare professionals. Usual care was described, highlighting (1) similarities and embedded practices, (2) heterogeneity and (3) subtle changes in care during the trial within and across sites.

CONCLUSIONS

We provide a feasible approach to defining usual care that can be practically adopted in different settings. Understanding usual care enhances the reliability of tested complex interventions, and informs research and policy priorities.

Dyadic interventions to promote physical activity and reduce sedentary behaviour: systematic review and meta-analysis

Several interventions have targeted dyads to promote physical activity (PA) or reduce sedentary behaviour (SB), but the evidence has not been synthesised. Sixty-nine studies were identified from MEDLINE, PsycINFO, and Web of Science, and 59 were included in the main meta-analyses (providing 72 independent tests). Intervention details, type of dyadic goal, participant characteristics, and methodological quality were extracted and their impact on the overall effect size was examined. Sensitivity analyses tested effect robustness to (a) the effects of other statistically significant moderators; (b) outliers; (c) data included for participants who were not the main target of the intervention. Dyadic interventions had a small positive, highly heterogeneous, effect on PA g = .203, 95% CI [0.123-0.282], compared to comparison conditions including equivalent interventions targeting individuals. Shared target-oriented goals (where both dyad members hold the same PA goal for the main target of the intervention) and peer/friend dyads were associated with larger effect sizes across most analyses. Dyadic interventions produced a small homogeneous reduction in SB. Given dyadic interventions promote PA over-and-above equivalent interventions targeting individuals, these interventions should be more widespread. However, moderating factors such as the types of PA goal and dyad need to be considered to maximise effects.

Surveying knowledge, practice and attitudes towards intervention fidelity within trials of complex healthcare interventions

Background

Intervention fidelity is the degree to which interventions have been implemented as intended by their developers. Assessing fidelity is crucial for accurate interpretation of intervention effectiveness, but fidelity is often poorly addressed within trials of complex healthcare interventions. The reasons for this are unclear, and information on the use of methods to enhance and assess fidelity in trials of complex interventions remains insufficient. This study aimed to explore the knowledge, practice and attitudes towards intervention fidelity amongst researchers, triallists and healthcare professionals involved with the design and conduct of trials of complex healthcare interventions.

Methods

An online survey consisting of closed and open-ended questions exploring four sections (Demographics, Fidelity knowledge, Practice and Attitudes) was conducted. This was an opportunistic sample of individuals with experience of direct involvement in trials of complex healthcare interventions (e.g. design/development, conduct, evaluation).

Results

Data from 264 participants representing 15 countries were analysed. The majority (65.9%, n = 174) of participants identified themselves as ‘Researchers’. The majority of participants were familiar with the term “intervention fidelity” (69.7%, n = 184) and indicated that fidelity is important (89.7%, n = 236). Mean self-reported understanding of fidelity was moderate. Although 68% (n = 182) had previously used strategies to assess (e.g. audio/video-recording sessions) and enhance (e.g. training manual) fidelity in trials of complex interventions, only a limited proportion of participants indicated always reporting these strategies in subsequent publications (30.9%, n = 56). Poor knowledge or understanding was the most commonly cited barrier to addressing intervention fidelity in trials (77.4%, n = 202). Over half of respondents (52.1%, n = 137) had never completed specific fidelity training or research, and the vast majority (89.7%, n = 236) would welcome specific training in this area.

Conclusion

Despite good awareness of intervention fidelity and its importance, poor knowledge and understanding appears to be a key factor limiting how intervention fidelity is addressed in trials of complex interventions. Participants identified a need for further training and education in this area. Additionally, clarification of the terminology, definition and components of intervention fidelity would facilitate better understanding of the concept. A discrepancy between participants’ use of fidelity strategies and subsequent reporting raises concerns around inadequate fidelity reporting in the trials literature.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-2838-6) contains supplementary material, which is available to authorized users.

A new method of applying randomised control study data to the individual patient: A novel quantitative patient-centred approach to interpreting composite end points

BACKGROUND

Modern randomised controlled trials typically use composite endpoints. This is only valid if each endpoint is equally important to patients but few trials document patient preference and seek the relative importance of components of combined endpoints. If patients weigh endpoints differentially, our interpretation of trial data needs to be refined.

METHODS AND RESULTS

We derive a quantitative, structured tool to determine the relative importance of each endpoint to patients. We then apply this tool to data comparing angioplasty with drug-eluting stents to bypass surgery. The survey was administered to patients undergoing cardiac catheterisation. A meta-analysis comparing coronary artery bypass grafting (CABG) to percutaneous coronary interventuin (PCI) was then performed using (a) standard MACE and (b) patient-centred MACE. Patients considered stroke worse than death (stroke 102.3 ± 19.6%, p < 0.01), and MI and repeat revascularisation less severe than death (61.9 ± 26.8% and 41.9 ± 25.4% respectively p < 0.01 for both). 7 RCTs (5251 patients) were eligible. Meta-analysis demonstrated that standard MACE occurs more frequently with PCI than surgery (OR 1.44; 95% CI 1.10 to 1.87; p = 0.007). Re-analysis using patient-centred MACE found no significant difference between PCI and CABG (OR 1.22, 95% CI 0.97 to 1.53; p = 0.10).

CONCLUSIONS

Patients do not consider the constituent endpoints of MACE equal. We derive a novel patient-centred metric that recognises and quantifies the differences attributed to each endpoint. When patient preference data are applied to contemporary trial results, there is no significant difference between PCI and CABG. Responses from individual patients in clinic could be used to give individual patients a recommendation that is truly personalised.