Estimating the number needed to treat from continuous outcomes in randomised controlled trials: methodological challenges and worked example using data from the UK Back Pain Exercise and Manipulation (BEAM) trial

Background Reporting numbers needed to treat (NNT) improves interpretability of trial results. It is unusual that continuous outcomes are converted to numbers of individual responders to treatment (i.e., those who reach a particular threshold of change); and deteriorations prevented are only rarely considered. We consider how numbers needed to treat can be derived from continuous outcomes; illustrated with a worked example showing the methods and challenges. Methods We used data from the UK BEAM trial (n = 1, 334) of physical treatments for back pain; originally reported as showing, at best, small to moderate benefits. Participants were randomised to receive 'best care' in general practice, the comparator treatment, or one of three manual and/or exercise treatments: 'best care' plus manipulation, exercise, or manipulation followed by exercise. We used established consensus thresholds for improvement in Roland-Morris disability questionnaire scores at three and twelve months to derive NNTs for improvements and for benefits (improvements gained+deteriorations prevented). Results At three months, NNT estimates ranged from 5.1 (95% CI 3.4 to 10.7) to 9.0 (5.0 to 45.5) for exercise, 5.0 (3.4 to 9.8) to 5.4 (3.8 to 9.9) for manipulation, and 3.3 (2.5 to 4.9) to 4.8 (3.5 to 7.8) for manipulation followed by exercise. Corresponding between-group mean differences in the Roland-Morris disability questionnaire were 1.6 (0.8 to 2.3), 1.4 (0.6 to 2.1), and 1.9 (1.2 to 2.6) points. Conclusion In contrast to small mean differences originally reported, NNTs were small and could be attractive to clinicians, patients, and purchasers. NNTs can aid the interpretation of results of trials using continuous outcomes. Where possible, these should be reported alongside mean differences. Challenges remain in calculating NNTs for some continuous outcomes

The effects of nudges: one-shot only?: Exploring the temporal spillover effects of a default nudge

Nudges, such as defaults, are generally found to be effective in guiding immediate behavioural decisions. However, little is known about whether the effect of a nudge can be lasting, meaning that it spills over to subsequent similar choices without the presence of a nudge. In three experiments, we explored the temporal spillover effects of a default nudge. The results of Experiments 1 (N = 1,077) and 2 (N = 1,036) suggest that nudging participants into completing a longer questionnaire affected their decision for the same behaviour a day later without the presence of a nudge. However, nudging participants into a healthier food choice in Experiment 3 (N = 969) did not result in such a temporal spillover effect. The results indicated that participants' change in attitude towards the nudged behaviour may partly explain the temporal spillover effects. These findings suggest that for some, but not all behaviours, default nudges may have the potential to yield temporal spillover effects and warrant a further investigation of boundary conditions and facilitators of the spillover effects of nudges.Prevention, Population and Disease management (PrePoD)Public Health and primary car

The effect of transparency on the temporal spillover effect of default nudges

Previous studies show that the effects of (non-transparent) nudges can spill over to later similar decisions without nudges. In the current study, we aimed to determine whether such nudge temporal spillover effects are affected by making nudges transparent. The latter is recommended to (partly) mitigate ethical concerns surrounding the use of nudges. In two experiments, we nudged participants to complete a longer version of a survey. Participants were randomly assigned to either a control, a non-disclosed nudge (using a default to promote taking the longer survey) condition or a disclosed nudge (in which the use of the default nudge was explained) condition. In both Study 1 (N = 1270) and Study 2 (N = 1258) we observed a temporal spillover effect of the disclosed nudge, suggesting that transparency does not negatively affect the temporal spillover effect.Public Health and primary car

When nudgees become nudgers: exploring the use of self-nudging to promote fruit intake

The current study explored (1) the immediate and prolonged effects of self-nudges promoting fruit intake in the home environment, (2) whether the effect of self-nudges on fruit intake persists after self-nudges are no longer used (i.e. a temporal spillover effect) and (3) whether self-nudges can install healthy eating habits that, in turn, explain the temporal spillover effect. Participants (N = 331) were randomly assigned to either a control or self-nudge condition in which they had to choose a self-nudge promoting fruit consumption for 8 weeks. Thereafter, participants were asked to remove the self-nudge for 1 week to assess a possible temporal spillover effect. Results showed a positive effect of the self-nudges on fruit consumption right after implementation that continued during the 8 weeks in which the self-nudge was implemented, which was accompanied by an increase in fruit intake habit strength. However, a mixed picture emerged regarding the temporal spillover effect and no support was found for a mediation effect of habit strength. Although this study is only a first exploration of self-nudging to increase healthy food consumption, results indicate that self-nudging may be a promising extension of traditional nudging that can influence behaviour beyond out-of-home settings.Prevention, Population and Disease management (PrePoD

Behavioural strategies to control the amount of food selected and consumed

Several factors within the food environment may stimulate overconsumption. The present study aimed to (1) identify behavioural strategies to cope with this environment to control the amount of food consumed, (2) examine the feasibility and usefulness of the strategies, and (3) evaluate the association between the strategies and body mass index (BMI). After the literature was screened for evidence of factors that contribute to the consumption of large amounts of food, 32 behavioural strategies were identified to overcome these influences (study 1). Subjectively reported feasibility and usefulness of the 32 behavioural strategies in weight management were explored using a pretest post-test study (study 2: n = 52). Additionally, two cross-sectional questionnaire studies (study 3a: n = 120 and study 3b: n = 278) were conducted to evaluate the association between the 32 behavioural strategies and BMI. The strategies were subjectively reported as feasible and useful in weight management. Frequent use of strategies discriminated non-overweight from overweight individuals, but did not discriminate overweight from obese individuals. In conclusion, the findings provided preliminary evidence for the acceptability and validity of the strategies. The effectiveness of the strategies for controlling the amount consumed should be further investigated, especially in overweight and obese participants

Associations between active video gaming and other energy-balance related behaviours in adolescents: a 24-hour recall diary study

Active video games may contribute to reducing time spent in sedentary activities, increasing physical activity and preventing excessive weight gain in adolescents. Active video gaming can, however, only be beneficial for weight management when it replaces sedentary activities and not other physical activity, and when it is not associated with a higher energy intake. The current study therefore examines the association between active video gaming and other energy-balance-related behaviours (EBRBs). Findings Adolescents (12–16 years) with access to an active video game and who reported to spend at least one hour per week in active video gaming were invited to participate in the study. They were asked to complete electronic 24-hour recall diaries on five randomly assigned weekdays and two randomly assigned weekend-days in a one-month period, reporting on time spent playing active and non-active video games and on other EBRBs. Findings indicated that adolescents who reported playing active video games on assessed days also reported spending more time playing non-active video games (Median¿=¿23.6, IQR¿=¿56.8 minutes per week) compared to adolescents who did not report playing active video games on assessed days (Median¿=¿10.0, IQR¿=¿51.3 minutes per week, P

Healthcare workers’ acceptability of influenza vaccination nudges: Evaluation of a real-world intervention

Nudges have been proposed as an effective tool to stimulate influenza vaccination uptake in healthcare workers. However, the success of such nudges in practice is heavily reliant on their acceptance by the intended healthcare worker population, which has not been thoroughly examined to date. This study investigated healthcare workers’ acceptability of diverse influenza vaccination nudges implemented in a real-world vaccination campaign and explored the relationship between nudge acceptability and vaccination uptake. A cross-sectional study was conducted among 244 Dutch hospital employees, following a hospital-wide influenza vaccination nudging intervention. A survey assessed healthcare workers’ perceived acceptability of ten distinct influenza vaccination nudges, along with their vaccination status and relevant covariates (e.g., general perceptions regarding influenza vaccination of healthcare workers). Influenza vaccination nudges in general were deemed acceptable, with reward-based nudges being the least accepted, while digital vaccination forms, a mobile vaccination post, peer vaccination, and digital vaccination reminders were most appreciated. A higher overall acceptance of these nudges was associated with a greater likelihood of being vaccinated, particularly in healthcare workers with favorable perceptions of influenza vaccination usefulness. Our findings suggest that influenza vaccination nudges are an accepted means to systematically promote immunization of healthcare workers, and thus present a viable strategy for public health policies aimed at this group

Вплив стану імуносупресії на реакцію відторгнення шкірного трансплантата у щурів

Background: Food portion sizes influence energy intake. Purpose: The purpose of this paper is to determine effectiveness of the “PortionControl@HOME” intervention on body mass index and portion control behavior. Methods: A randomized controlled trial among 278 overweight and obese participants was conducted. PortionControl@HOME aimed to increase: portion size awareness, portion control behavior, portion control cooking skills, and to create a home environment favoring portion control. Results: Intention-to-treat multi-level regression analysis indicated statistically significant effects of the intervention on portion control behavior at 3, 6, and 12 months follow-up. The effect on body mass index was significant only at 3 months follow-up and when outliers (n = 3) were excluded (B = −0.45; 95 %CI = −0.88 to −0.04). The intervention effect on body mass index was mediated by portion control behavior. Conclusions: The intervention improves portion control behavior, which in turn influence body mass index. Once the intervention ceased, sustained effects on body mass index were no longer evident. (Current-Controlled-Trials ISRCTN12363482)

Initial psychological responses to influenza A, H1N1 ("Swine flu")

Background The outbreak of the pandemic flu, Influenza A H1N1 (Swine Flu) in early 2009, provided a major challenge to health services around the world. Previous pandemics have led to stockpiling of goods, the victimisation of particular population groups, and the cancellation of travel and the boycotting of particular foods (e.g. pork). We examined initial behavioural and attitudinal responses towards Influenza A, H1N1 ("Swine flu") in the six days following the WHO pandemic alert level 5, and regional differences in these responses. Methods 328 respondents completed a cross-sectional Internet or paper-based questionnaire study in Malaysia (N = 180) or Europe (N = 148). Measures assessed changes in transport usage, purchase of preparatory goods for a pandemic, perceived risk groups, indicators of anxiety, assessed estimated mortality rates for seasonal flu, effectiveness of seasonal flu vaccination, and changes in pork consumption Results 26% of the respondents were 'very concerned' about being a flu victim (42% Malaysians, 5% Europeans, p < .001). 36% reported reduced public transport use (48% Malaysia, 22% Europe, p < .001), 39% flight cancellations (56% Malaysia, 17% Europe, p < .001). 8% had purchased preparatory materials (e.g. face masks: 8% Malaysia, 7% Europe), 41% Malaysia (15% Europe) intended to do so (p < .001). 63% of Europeans, 19% of Malaysians had discussed the pandemic with friends (p < .001). Groups seen as at 'high risk' of infection included the immune compromised (mentioned by 87% respondents), pig farmers (70%), elderly (57%), prostitutes/highly sexually active (53%), and the homeless (53%). In data collected only in Europe, 64% greatly underestimated the mortality rates of seasonal flu, 26% believed seasonal flu vaccination gave protection against swine flu. 7% had reduced/stopped eating pork. 3% had purchased anti-viral drugs for use at home, while 32% intended to do so if the pandemic worsened. Conclusion Initial responses to Influenza A show large regional differences in anxiety, with Malaysians more anxious and more likely to reduce travel and to buy masks and food. Discussions with family and friends may reinforce existing anxiety levels. Particular groups (homosexuals, prostitutes, the homeless) are perceived as at greater risk, potentially leading to increased prejudice during a pandemic. Europeans underestimated mortality of seasonal flu, and require more information about the protection given by seasonal flu inoculation