Placebo adherence and its association with morbidity and mortality in the studies of left ventricular dysfunction

Placebo administration for dry eye disease: a level I evidence based systematic review and meta-analysis

Background

The efficacy of various common treatment options for dry eye disease (DED) has been investigated against placebo. However, the potential beneficial effect of placebo in the management of DED is still unclear.

Aim

This meta-analysis investigated the impact of placebo administration in DED in Ocular Surface Disease Index (OSDI), Schirmer I test (SIT), tear breakup time (TBUT), corneal staining, and complications.

Method

This meta-analysis and systematic review was conducted according to the 2020 PRISMA guidelines. In March 2022, Pubmed, Web of Science, Google Scholar, and Embase were accessed. All the randomised clinical trials which investigated any active treatment against a placebo control group were considered. The following data were extracted at baseline and at last follow-up: Ocular Surface Disease Index (OSDI), tear breakup time test (TBUT), Schirmer I test (SIT), corneal staining.

Results

Data from 56 studies (12,205 patients) were retrieved. Placebo administration is not effective in improving TBUT (P = 0.3), OSDI (P = 0.2), SIT (P = 0.1) and corneal staining (P = 0.1) from baseline to last follow-up. Active treatment led to a higher TBUT and SIT compared to placebo administration (P < 0.0001). The active treatment resulted in a lower OSDI compared to placebo administration (P = 0.0005). Five studies reported data on the corneal staining. No difference was found between placebo administration and active treatment (P = 0.8).

Conclusion

Placebo administration does not impact symptoms of DED and can be successfully employed to evaluate the efficacy of active treatments.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11096-022-01439-y.

Patient expectations shape convalescence after major liver surgery - A prospective, randomized study

BACKGROUND

Several studies suggest an important influence of patient expectations on outcomes. We hypothesized that patient expectations with regard to length of postoperative stay influence convalescence after liver resections.

METHOD

This prospective, randomized study compared patients who were preoperatively either informed to be expected to stay 7-10 days (short arm) or 12-16 days (long arm) after major liver resections (≥4 segments). Additionally, psychological traits were assessed using questionnaires and the time to fulfillment of objective discharge criteria [oral analgesics only, first bowel movement, ability to tolerate solid food, full mobilization, no complications which need general anesthesia (>CD IIIa)] was defined as the primary endpoint.

RESULTS

Patients in the short arm reached the objective discharge criteria after 8.39 days (SD 3.60), while patients in the long arm needed 12.73 days (SD 3.43) (p = 0.001). The actual length of stay in the short arm was 12.00 (IQR 8-16) and 19.3 days in the long arm (IQR 14-26) (p = 0.008). A more pronounced self-efficacy correlated with earlier fulfillment of the objective discharge criteria (p = 0.048), whereas patients placing a high value on their health needed more time (p = 0.049).

CONCLUSION

The expectation of a shorter length of stay results in a quicker objective, physical patient convalescence after major liver resections.

Placebo effect in pharmacological management of fibromyalgia: a meta-analysis

INTRODUCTION

The management of fibromyalgia involves a combination of pharmacological and non-pharmacological treatments.

SOURCE OF DATA

Recently published literature in PubMed, Google Scholar and Embase databases.

AREAS OF AGREEMENT

Several pharmacological and non-pharmacological strategies have been proposed for the management of fibromyalgia. However, the management of fibromyalgia remains controversial. The administration of placebo has proved to be more effective than no treatment in many clinical settings and evidence supports the 'therapeutic' effects of placebo on a wide range of symptoms.

AREAS OF CONTROVERSY

The placebo effect is believed to impact the clinical outcomes, but its actual magnitude is controversial.

GROWING POINTS

A meta-analysis comparing pharmacological management versus placebo administration for fibromyalgia was conducted.

AREAS TIMELY FOR DEVELOPING RESEARCH

Drug treatment resulted to be more effective than placebo administration for the management of fibromyalgia. Nevertheless, placebo showed a beneficial effect in patients with fibromyalgia. Treatment-related adverse events occurred more frequently in the drug treatment.

LEVEL OF EVIDENCE

I, Bayesian network meta-analysis of double-blind randomized clinical trials.

Sacubitril/Valsartan Adherence and Postdischarge Outcomes Among Patients Hospitalized for Heart Failure With Reduced Ejection Fraction

OBJECTIVES

The authors sought to investigate associations between sacubitril/valsartan adherence and clinical outcomes after hospitalization for heart failure with reduced ejection fraction (HFrEF).

BACKGROUND

Sacubitril/valsartan improves outcomes in HFrEF, though the extent to which medication adherence is associated with outcomes in routine care is less well characterized.

METHODS

The authors analyzed patients aged ≥65 years hospitalized for HFrEF within the Get With the Guidelines-Heart Failure registry linked with Medicare claims between October 2015 and September 2018 who were discharged with sacubitril/valsartan. Sacubitril/valsartan adherence was assessed using medication fills to calculate proportion of days covered (PDC) through 90 days postdischarge. Associations between postdischarge adherence (PDC < or ≥80%) and risk of readmission and death within 1 year were examined by comparing cumulative incidences and adjusted event rates.

RESULTS

Among 897 patients prescribed sacubitril/valsartan at discharge, 295 (32.9%) had PDC ≥80% and 602 (67.1%) had PDC <80%. Baseline characteristics were balanced between groups. Compared with patients with PDC <80%, patients with PDC ≥80% had a significantly lower adjusted hazard of all-cause re-hospitalization (HR: 0.66; [95% CI: 0.48-0.89]) and death (HR: 0.42; [0.22-0.79]) at 90 days and at 1 year (HR: 0.69; [0.56-0.86] and HR: 0.53; [0.38-0.74], respectively). For every 5 percentage point increase in PDC, patients experienced a significant reduction in rehospitalization (HR: 0.98; [0.97-0.99]) and death (HR: 0.96; [0.94-0.97]) at 1 year.

CONCLUSIONS

In patients hospitalized for HFrEF and discharged on sacubitril/valsartan, high adherence to sacubitril/valsartan within 90 days after discharge was associated with substantially lower rates of readmission and death. Additional efforts to improve adherence with sacubitril/valsartan and other guideline-directed medical therapies in HFrEF are warranted.

Healing in a Social Context: The Importance of Clinician and Patient Relationship

When a patient presents to a health provider, the course of the disorder is composed of three effects: natural effects, specific effects, and contextual effects. Part of the contextual effect is due to the relationship between the healer and the patient. Social healing appears to be present in eusocial species and particularly well-developed in humans. Evidence for the importance of the relationship in healing is found in placebo studies, including placebo analgesics, medicine, and psychotherapy. Although the theory for how the relationship is therapeutic is not well-developed, four possible mechanisms are discussed. The implications for health care and the treatment of pain are discussed.

Science of Salt: A regularly updated systematic review of salt and health outcomes studies (April to October 2018)

The Science of Salt reviews identify, summarize, and critically appraise published studies on dietary salt and health outcomes according to pre-specified methods. This review covers the period April 3 to October 30, 2018. Here, nineteen studies that fit pre-specified criteria for review and summary are included. Three of these, one prospective cohort study, one randomized controlled trial, and a post hoc analysis of the Dietary Approaches to Stop Hypertension (DASH) sodium trial fulfilled the quality criteria for detailed critical appraisal, including risk of bias assessment, and commentary. Two trials demonstrated a positive association between salt intake and blood pressure. In a cohort of older Italians, increased risk of total mortality was observed with salt intake less than ~16 g/d (6300 mg sodium/d) at baseline; no association existed for incident cardiovascular disease (CVD) or CVD mortality. The paucity of published studies which met our criteria for methodological quality is of concern.

Follow-up tests and outcomes for patients undergoing percutaneous coronary intervention: analysis of a Japanese administrative database

Follow-up tests after percutaneous coronary intervention (PCI) are considered inappropriate for asymptomatic patients. Despite this perception, many cardiologists conduct follow-up tests as routine practice. The objective of this study was to investigate the survival benefits of follow-up testing after PCI in a real-world setting in Japan. A nationwide Japanese administrative database was used to identify unselected patients who underwent PCI with stent implantation between January 2010 and December 2013. We used time-dependent Cox proportional hazards models to evaluate the association between follow-up testing and outcomes. The primary outcome was the composite of all-cause death and acute myocardial infarction (AMI). Among a total of 21,409 patients, 15,095 (70.5%) completed follow-up testing, of whom 9814 (45.0%) underwent coronary angiography. During a median of 2.7 years of observation, the primary outcome occurred less frequently for patients who underwent follow-up testing (1.21 vs. 4.51% per year; adjusted hazard ratio, 0.59; 95% CI 0.52-0.67; p < 0.001). Individual rates of all-cause death and AMI were also lower for the patients who underwent follow-up testing. Follow-up testing was associated with a lower risk of all-cause death and/or AMI. However, because of the unexpectedly large effect and many limitations of the administrative data, our findings should be further investigated to assess the net benefit of follow-up tests. In addition, we do not intend to encourage routine follow-up tests for patients without clear clinical indications. Follow-up tests should be conducted in accordance with clinical indications.

Association of the magnitude of weight loss and changes in physical fitness with long-term cardiovascular disease outcomes in overweight or obese people with type 2 diabetes: a post-hoc analysis of the Look AHEAD randomised clinical trial

BACKGROUND

Findings from the Look AHEAD trial showed no significant reductions in the primary outcome of cardiovascular disease incidence in adults with type 2 diabetes randomly assigned to an intensive lifestyle intervention for weight loss compared with those randomly assigned to diabetes support and education (control). We examined whether the incidence of cardiovascular disease in Look AHEAD varied by changes in weight or fitness.

METHODS

Look AHEAD was a randomised clinical trial done at 16 clinical sites in the USA, recruiting patients from Aug 22, 2001, to April 30, 2004. In the trial, 5145 overweight or obese adults aged 45-76 years with type 2 diabetes were assigned (1:1) to an intensive lifestyle intervention or diabetes support and education. In this observational, post-hoc analysis, we examined the association of magnitude of weight loss and fitness change over the first year with incidence of cardiovascular disease. The primary outcome of the trial and of this analysis was a composite of death from cardiovascular causes, non-fatal acute myocardial infarction, non-fatal stroke, or admission to hospital for angina. The secondary outcome included the same indices plus coronary artery bypass grafting, carotid endartectomy, percutaneous coronary intervention, hospitalisation for congestive heart failure, peripheral vascular disease, or total mortality. We adjusted analyses for baseline differences in weight or fitness, demographic characteristics, and risk factors for cardiovascular disease. The Look AHEAD trial is registered with ClinicalTrials.gov, number NCT00017953.

FINDINGS

For the analyses related to weight change, we excluded 311 ineligible participants, leaving a population of 4834; for the analyses related to fitness change, we excluded 739 participants, leaving a population of 4406. In analyses of the full cohort (ie, combining both study groups), over a median 10·2 years of follow-up (IQR 9·5-10·7), individuals who lost at least 10% of their bodyweight in the first year of the study had a 21% lower risk of the primary outcome (adjusted hazard ratio [HR] 0·79, 95% CI 0·64-0·98; p=0·034) and a 24% reduced risk of the secondary outcome (adjusted HR 0·76, 95% CI 0·63-0·91; p=0·003) compared with individuals with stable weight or weight gain. Achieving an increase of at least 2 metabolic equivalents in fitness change was associated with a significant reduction in the secondary outcome (adjusted HR 0·77, 95% CI 0·61-0·96; p=0·023) but not the primary outcome (adjusted HR 0·78, 0·60-1·03; p=0·079). In analyses treating the control group as the reference group, participants in the intensive lifestyle intervention group who lost at least 10% of their bodyweight had a 20% lower risk of the primary outcome (adjusted HR 0·80, 95% CI 0·65-0·99; p=0·039), and a 21% lower risk of the secondary outcome (adjusted HR 0·79, 95% CI 0·66-0·95; p=0·011); however, change in fitness was not significantly associated with a change in the primary outcome.

INTERPRETATION

The results of this post-hoc analysis of Look AHEAD suggest an association between the magnitude of weight loss and incidence of cardiovascular disease in people with type 2 diabetes. These findings suggest a need to continue to refine approaches to identify individuals who are most likely to benefit from lifestyle interventions and to develop strategies to improve the magnitude of sustained weight loss with lifestyle interventions.

FUNDING

US National Institute of Diabetes and Digestive and Kidney Diseases.

The neuroscience of placebo effects: connecting context, learning and health

Placebo effects are beneficial effects that are attributable to the brain-mind responses to the context in which a treatment is delivered rather than to the specific actions of the drug. They are mediated by diverse processes--including learning, expectations and social cognition--and can influence various clinical and physiological outcomes related to health. Emerging neuroscience evidence implicates multiple brain systems and neurochemical mediators, including opioids and dopamine. We present an empirical review of the brain systems that are involved in placebo effects, focusing on placebo analgesia, and a conceptual framework linking these findings to the mind-brain processes that mediate them. This framework suggests that the neuropsychological processes that mediate placebo effects may be crucial for a wide array of therapeutic approaches, including many drugs.

Causal inference methods to assess safety upper bounds in randomized trials with noncompliance

BACKGROUND

Premature discontinuation and other forms of noncompliance with treatment assignment can complicate causal inference of treatment effects in randomized trials. The intent-to-treat analysis gives unbiased estimates for causal effects of treatment assignment on outcome, but may understate potential benefit or harm of actual treatment. The corresponding upper confidence limit can also be underestimated.

PURPOSE

To compare estimates of the hazard ratio and upper bound of the two-sided 95% confidence interval from causal inference methods that account for noncompliance with those from the intent-to-treat analysis.

METHODS

We used simulations with parameters chosen to reflect cardiovascular safety trials of diabetes drugs, with a focus on upper bound estimates relative to 1.3, based on regulatory guidelines. A total of 1000 simulations were run under each parameter combination for a hypothetical trial of 10,000 total subjects randomly assigned to active treatment or control at 1:1 ratio. Noncompliance was considered in the form of treatment discontinuation and cross-over at specified proportions, with an assumed true hazard ratio of 0.9, 1, and 1.3, respectively. Various levels of risk associated with being a non-complier (independent of treatment status) were evaluated. Hazard ratio and upper bound estimates from causal survival analysis and intent-to-treat were obtained from each simulation and summarized under each parameter setting.

RESULTS

Causal analysis estimated the true hazard ratio with little bias in almost all settings examined. Intent-to-treat was unbiased only when the true hazard ratio = 1; otherwise it underestimated both benefit and harm. When upper bound estimates from intent-to-treat were ≥1.3, corresponding estimates from causal analysis were also ≥1.3 in almost 100% of the simulations, regardless of the true hazard ratio. When upper bound estimates from intent-to-treat were <1.3 and the true hazard ratio = 1, corresponding upper bound estimates from causal analysis were ≥1.3 in up to 66% of the simulations under some settings.

LIMITATIONS

Simulations cannot cover all scenarios for noncompliance in real randomized trials.

CONCLUSION

Causal survival analysis was superior to intent-to-treat in estimating the true hazard ratio with respect to bias in the presence of noncompliance. However, its large variance should be considered for safety upper bound exclusion especially when the true hazard ratio = 1. Our simulations provided a broad reference for practical considerations of bias-variance trade-off in dealing with noncompliance in cardiovascular safety trials of diabetes drugs. Further research is warranted for the development and application of causal inference methods in the evaluation of safety upper bounds.

Effectiveness of a focused, brief psychoeducation program for parents of ADHD children: improvement of medication adherence and symptoms

OBJECTIVE

To evaluate the efficacy of a psychoeducation program for parents of children with ADHD in enhancing adherence to pharmacological treatment and improving clinical symptoms.

METHODS

We developed a psychoeducation program based on the theory of planned behavior (TPB). Eighty-nine children with ADHD were cluster randomly assigned for their families to receive 3 months of well-structured psychoeducation (intervention group, n=44) or only general clinical counseling (control group, n=45). Parents in the intervention group were given an expert lecture (with slides and a parent manual), attended two expert-guided parent group sessions, and were invited to join a professional-guided online community. Measurement of parents' knowledge about ADHD, components of the TPB model, and child ADHD symptoms were taken before and after intervention. Medication adherence was assessed thoroughly at the end of the first and third months. Satisfaction with the psychoeducation program was assessed only in the intervention group. Two-independent-samples t-test, ANOVA, and chi-square test were employed to compare differences between groups.

RESULTS

Compared to the control group, medication adherence in the intervention group was significantly higher after 1 and 3 months (97.7% intervention vs 75.6% control, P=0.002, and 86.4% intervention vs 53.3% control, P=0.001, respectively). Accordingly, the ADHD rating scale scores were lower in the intervention group than the control group after intervention (33.7±5.4 vs 45.1±7.9, P=0.008). Greater improvements in parents' knowledge about ADHD and many components of the TPB model were observed in the intervention group, especially increased intention to adhere to medication, compared to the control group (P<0.001).

CONCLUSION

This psychoeducation program had a positive impact on both medication adherence and clinical symptoms of ADHD children. It could be considered as a potential beneficial supplement to clinical practice.

Intention-to-treat analyses and missing data approaches in pharmacotherapy trials for alcohol use disorders

OBJECTIVES

Intention to treat (ITT) is an analytic strategy for reducing potential bias in treatment effects arising from missing data in randomised controlled trials (RCTs). Currently, no universally accepted definition of ITT exists, although many researchers consider it to require either no attrition or a strategy to handle missing data. Using the reports of a large pool of RCTs, we examined discrepancies between the types of analyses that alcohol pharmacotherapy researchers stated they used versus those they actually used. We also examined the linkage between analytic strategy (ie, ITT or not) and how missing data on outcomes were handled (if at all), and whether data analytic and missing data strategies have changed over time.

DESIGN

Descriptive statistics were generated for reported and actual data analytic strategy and for missing data strategy. In addition, generalised linear models determined changes over time in the use of ITT analyses and missing data strategies.

PARTICIPANTS

165 RCTs of pharmacotherapy for alcohol use disorders.

RESULTS

Of the 165 studies, 74 reported using an ITT strategy. However, less than 40% of the studies actually conducted ITT according to the rigorous definition above. Whereas no change in the use of ITT analyses over time was found, censored (last follow-up completed) and imputed missing data strategies have increased over time, while analyses of data only for the sample actually followed have decreased.

CONCLUSIONS

Discrepancies in reporting versus actually conducting ITT analyses were found in this body of RCTs. Lack of clarity regarding the missing data strategy used was common. Consensus on a definition of ITT is important for an adequate understanding of research findings. Clearer reporting standards for analyses and the handling of missing data in pharmacotherapy trials and other intervention studies are needed.

Adherence, expectations and the placebo response: why is good adherence to an inert treatment beneficial?

OBJECTIVE

The current study sought to better understand why good adherence to a placebo treatment has been reliably associated with health benefits. We proposed a model where initial expectations shape adherence, which then influences subsequent expectations that affect placebo response.

DESIGN

Seventy-two participants were told that they were enrolling in a study of physical activity and memory, and were asked to increase their physical activity by 35% for two weeks (placebo treatment).

MAIN OUTCOME MEASURES

Adherence to this physical activity target was measured by pedometer. Expectations and short-term memory (free recall) were assessed before and after physical activity.

RESULTS

Initial expectations predicted adherence to physical activity (r = .27, p < .03), but adherence did not predict subsequent expectations (r = .06, p = .60). Testing a multi-step meditational model revealed that initial expectations predicted better memory even after controlling for adherence, subsequent expectations, baseline memory and gender (c' = 1.10, 95% CI = .46-1.74). Stronger expectations for memory improvement predicted better memory performance, but adherence and later expectations did not mediate this association.

CONCLUSIONS

Good adherence to a placebo may reflect strong treatment expectations which may convey benefits by enhancing the non-specific effects of treatment.

To adhere or not, and what we can do to help

Two factors predict treatment outcome, how effective the treatment is and whether the patient takes or follows the treatment plan. As clinicians or scientists, we strive to develop newer and more effective treatments, both pharmacological and non-pharmacological to improve treatment outcome in our patient population. Adherence is the single most modifiable factor associated with treatment outcome, yet how often is the issue of adherence addressed in clinical consultations? The best treatment is rendered useless if not adhered to. Initial adherence rates are low and get worse with time, but methodological difficulties in studies make it difficult to determine both the clinical implication of suboptimal adherence and successful strategies. Further research should apply more rigour to the area of definition and measurement, be sufficiently powered and long term, and measure possible confounders, to allow for an understanding on the link and impact between adherence and clinical outcome. This article reviews some of the main issues with regard to adherence and cost implications of suboptimal adherence and suggests future directions.

Two character traits associated with adherence to long term therapies

Adherence is defined as the adequacy between the behaviours of patients and their medical prescriptions. Adherence is a general behaviour, which can explain why patients in the placebo arm of randomised clinical trials have a lower mortality rate when they are adherent. We propose that this behaviour is related to two character traits: patience (capacity to give priority to the future) and, more provocatively, obedience. To support this claim, we bring arguments from the literature and from two published personal studies. We previously showed that type 2 diabetic patients who respond as non-adherers to a questionnaire on adherence to medication and to whom one proposes a fictitious monetary choice between receiving 500 euros today or waiting one year to receive 1500 euros never make the remote choice. We also showed that obese diabetic patients who declare that they do not fasten their seat belt when they are seated in the rear of a car are more often non-adherent concerning medication than those patients who claim that they follow this road safety recommendation. Thus, one of the roles of empowerment and patient education could be to encourage the patients, if they wish it, to replace passive adherence behaviours with conscious active choices.

Placebo adherence and mortality in the Heart and Estrogen/Progestin Replacement Study

BACKGROUND

Analyses from double-blind randomized trials have reported lower mortality among participants who were more adherent to placebo compared with those who were less adherent. We explored this phenomenon by analyzing data from the placebo arm of the Heart and Estrogen/Progestin Replacement Study (HERS), a randomized, double-blind, placebo-controlled trial of estrogen plus progestin for secondary prevention of coronary heart disease in postmenopausal women. Our primary aim was to measure and explain the association between adherence to placebo and total mortality among the placebo-allocated participants in the HERS. Secondary aims included assessment of the association between placebo adherence and cause-specific morbidity and mortality.

METHODS

Participants with "higher placebo adherence" were defined as having taken at least 75% of their placebo study medication during each individual's participation in the study, whereas those with "lower placebo adherence" took less than 75%. The primary outcome was in-study all-cause mortality.

RESULTS

More adherent participants had significantly lower total mortality compared with less adherent participants (hazard ratio, 0.52; 95% confidence interval, 0.29-0.93). Adjusting for available confounders did not change the magnitude or significance of the estimates. Analyses revealed that the association of higher adherence and mortality might be explained, in part, by time-dependent confounding.

CONCLUSIONS

Analyses of the HERS data support a strong association between adherence to placebo study medication and mortality. Although probably not due to simple confounding by healthy lifestyle factors, the underlying mechanism for the association remains unclear. Further analyses of this association are necessary to explain this observation.

Adherence to placebo and mortality in the Beta Blocker Evaluation of Survival Trial (BEST)

BACKGROUND

Randomized controlled trials have reported lower mortality among patients who adhere to placebo compared with those who do not. We explored this phenomenon by reanalyzing data from the placebo arm of the Beta Blocker Evaluation of Survival Trial (BEST), a randomized, double-blind, placebo-controlled trial of bucindolol and mortality.

AIMS

Our primary aim was to measure and explain the association between adherence to placebo and total mortality among the placebo-allocated participants in the BEST trial. Secondary aims included assessment of the association between placebo adherence and cause-specific mortality.

METHODS

Participants with "higher placebo adherence" were defined as having taken at least 75% of their placebo study medication over the entire course of each individual's participation in the study, while those with "lower placebo adherence" took <75%. Primary outcome was in-study all-cause mortality. To account for confounding, we adjusted for all available modifiable, non-modifiable and psychosocial variables.

RESULTS

Adherent participants had a significantly lower total mortality compared to less-adherent participants (HR=0.61, 95% Confidence Interval: 0.46-0.82). Adjusting for available confounders did not change the magnitude or significance of the estimates. When considering cause-specific mortality, CVD and pump failure showed similar associations.

CONCLUSIONS

Analyses of the BEST trial data support a strong association between adherence to placebo study medication and total mortality. While probably not due to publication bias or simple confounding by healthy lifestyle factors, the underlying explanation for the association remains a mystery. Prospective examination of this association is necessary to better understand the underlying mechanism of this observation.

New evidence relating to the health impact of reducing salt intake

This paper is a Position Statement from an 'ad hoc' Scientific Review Subcommittee of the PAHO/WHO Regional Expert Group on Cardiovascular Disease Prevention through Dietary Salt Reduction. It is produced in response to requests from representatives of countries of the Pan-American Region of WHO needing clarification on two recent publications casting doubts on the appropriateness of population wide policies to reduce salt intake for the prevention of cardiovascular disease. The paper provides a brief background, a critical appraisal of the recent reports and explanations as why the implications have been mis-interpreted. The paper concludes that the benefits of salt reduction are clear and consistent, and reinforces the recommendations outlined by PAHO/WHO and other organizations worldwide for a population reduction in salt intake to prevent strokes, heart attacks and other cardiovascular events.

A systematic review of the impact of adherence on the effectiveness of e-therapies

Background

As the popularity of e-therapies grows, so too has the body of literature supporting their effectiveness. However, these interventions are often plagued by high attrition rates and varying levels of user adherence. Understanding the role of adherence may be crucial to understanding how program usage influences the effectiveness of e-therapy interventions.

Objective

The aim of this study was to systematically review the e-therapy literature to (1) describe the methods used to assess adherence and (2) evaluate the association of adherence with outcome of these interventions.

Methods

A systematic review of e-therapy interventions was conducted across disease states and behavioral targets. Data were collected on adherence measures, outcomes, and analyses exploring the relationship between adherence measures and outcomes.

Results

Of 69 studies that reported an adherence measure, only 33 (48%) examined the relationship between adherence and outcomes. The number of logins was the most commonly reported measure of adherence, followed by the number of modules completed. The heterogeneity of adherence and outcome measures limited analysis. However, logins appeared to be the measure of adherence most consistently related to outcomes in physical health interventions, while module completion was found to be most related to outcomes in psychological health interventions.

Conclusions

There is large variation in the reporting of adherence and the association of adherence with outcomes. A lack of agreement about how best to measure adherence is likely to contribute to the variation in findings. Physical and psychological outcomes seem influenced by different types of adherence. A composite measure encompassing time online, activity completion, and active engagements with the intervention may be the best measure of adherence. Further research is required to establish a consensus for measuring adherence and to understand the role of adherence in influencing outcomes.