Joel Crawford

Background: Extant digital multiple health behavior change interventions have shown promise in various populations; however, evidence for a broader approach among the general population is lacking. Moreover, existing interventions often contain several components but are typically assessed as a whole, meaning it remains unclear to what extent individual components contribute to intervention effects and how they may interact to influence health outcomes. Objective: This study estimates the effects of 6 components of a digital health behavior change intervention on alcohol, diet, physical activity, and smoking outcomes among individuals searching for help online. Methods: A double-blind randomized factorial trial design with 6 two-level factors was used. Adults from the general public in Sweden who were seeking help to change their behaviors were recruited through web searches and social media. Participants were eligible if they were 18 years or older and had at least one health behavior classified as unhealthy. Effects of 6 components were estimated: screening/feedback, goal-setting/planning, motivation, skills/know-how, mindfulness, and self-authored SMS text messages. Primary outcomes were weekly alcohol consumption and frequency of heavy episodic drinking, average daily fruit and vegetable consumption, weekly moderate-to-vigorous physical activity, and 4-week point-prevalence smoking. Results: A total of 5419 individuals were randomized. Overall, the screening/feedback component was the most effective for changing health behaviors, along with goal-setting/planning and motivation to change. In particular, there was evidence that screening/feedback increased average daily portions of fruit and vegetables at 2 months (mean difference 0.17, compatibility interval [CoI] 0.09-0.25, probability of effect [POE] >99.9%) and at 4 months (mean difference 0.13, CoI 0.04-0.21, POE 99.9%) and reduced the frequency of heavy episodic drinking at 4 months (incidence rate ratio 0.91, CoI 0.81-1.03, POE 94.2%). Components also interacted to further improve health outcomes, most notably the combination of screening/feedback with motivation to change, which further increased fruit and vegetable consumption (2 months: mean difference 0.20, CoI 0.09-0.30, POE >99.9%; 4 months: mean difference 0.17, CoI 0.05-0.29, POE 99.8%). Conclusions: The results from this study contribute to the development of more effective interventions by providing novel insights into the effects of individual and pairwise components of complex digital health behavior change interventions. Trial Registration: ISRCTN Registry ISRCTN16420548; http://www.isrctn.com/ISRCTN16420548 International Registered Report Identifier (IRRID): RR2-10.1136/bmjopen-2022-061024

Background: Smoking is a leading cause of mortality and morbidity worldwide. Efforts to reduce smoking prevalence have used SMS text message–based interventions, which typically send participants a series of short, informational, motivational, and practical messages over a set period. Evidence highlights the efficacy of using this approach to support smoking cessation, with such trials typically reporting the average treatment effects, in which causal inference is made regarding the average effect of a treatment on a heterogeneous sample. Nonetheless, using this approach to assessing treatment effects means we are unable to account for individual factors that impact the effectiveness of a treatment on outcomes, such as age, gender, and genetics. Objective: This study aimed to estimate the individualized effects of an SMS text message–based smoking cessation intervention to ascertain which individuals benefited the most and least during an effectiveness trial. Methods: Data from a randomized controlled trial including 1012 adults from the Swedish general population were used. The trial assessed the effects of an SMS text message–based intervention, NEXit (Nicotine Exit), that aimed to change behavior by increasing the importance of change, boosting knowledge on how to change, and instilling confidence for change. Outcomes assessed in the trial were prolonged abstinence and point prevalence of smoking cessation. Individualized treatment effects were modeled using baseline factors (demographics, psychosocial variables, and past behavior) to study who benefited the most and least from the intervention. Results: For prolonged abstinence, there was evidence of heterogeneous effects, with those benefiting the most from NEXit being older adults, female participants, individuals with high confidence in their ability to quit, and those who believed that quitting was important. For point prevalence abstinence, older individuals and those reporting high confidence in the ability to quit, the importance of quitting, and knowledge for change benefited the most. For both outcomes, individuals who reported smoking for a longer duration and smoking more at baseline benefited less. Conclusions: The results demonstrate how individuals respond differently to an SMS text message–based smoking cessation intervention. This provides an insight into who benefits the most and least from the intervention in terms of demographics, baseline characteristics, and behaviors. The study highlights which individuals need to be specifically targeted and/or have content developed to suit their individual needs to further reduce the prevalence of smoking.

BACKGROUND Extant digital multiple health behavior change interventions have shown promise in various populations; however, evidence for a broader approach among the general population is lacking. Moreover, existing interventions often contain several components but are typically assessed as a whole, meaning it remains unclear to what extent individual components contribute to intervention effects and how they may interact to influence health outcomes. OBJECTIVE This study estimates the effects of 6 components of a digital health behavior change intervention on alcohol, diet, physical activity, and smoking outcomes among individuals searching for help online. METHODS A double-blind randomized factorial trial design with 6 two-level factors was used. Adults from the general public in Sweden who were seeking help to change their behaviors were recruited through web searches and social media. Participants were eligible if they were 18 years or older and had at least one health behavior classified as unhealthy. Effects of 6 components were estimated: screening/feedback, goal-setting/planning, motivation, skills/know-how, mindfulness, and self-authored SMS text messages. Primary outcomes were weekly alcohol consumption and frequency of heavy episodic drinking, average daily fruit and vegetable consumption, weekly moderate-to-vigorous physical activity, and 4-week point-prevalence smoking. RESULTS A total of 5419 individuals were randomized. Overall, the screening/feedback component was the most effective for changing health behaviors, along with goal-setting/planning and motivation to change. In particular, there was evidence that screening/feedback increased average daily portions of fruit and vegetables at 2 months (mean difference 0.17, compatibility interval [CoI] 0.09-0.25, probability of effect [POE] >99.9%) and at 4 months (mean difference 0.13, CoI 0.04-0.21, POE 99.9%) and reduced the frequency of heavy episodic drinking at 4 months (incidence rate ratio 0.91, CoI 0.81-1.03, POE 94.2%). Components also interacted to further improve health outcomes, most notably the combination of screening/feedback with motivation to change, which further increased fruit and vegetable consumption (2 months: mean difference 0.20, CoI 0.09-0.30, POE >99.9%; 4 months: mean difference 0.17, CoI 0.05-0.29, POE 99.8%). CONCLUSIONS The results from this study contribute to the development of more effective interventions by providing novel insights into the effects of individual and pairwise components of complex digital health behavior change interventions. CLINICALTRIAL ISRCTN Registry ISRCTN16420548; http://www.isrctn.com/ISRCTN16420548 INTERNATIONAL REGISTERED REPORT RR2-10.1136/bmjopen-2022-061024

Introduction: Risky drinking is prevalent in European countries despite health authorities issuing guidelines created to support individuals to make informed choices about their alcohol intake. The current study explored personal perceptions of risky drinking, perceptions of the personal relevance of guidelines, and the processes used to form perceptions. Method: Three hundred and eight participants from Sweden and the UK completed an online survey containing open-ended questions about perceptions of risky drinking and personal relevance of drinking guidelines. Data was analysed using Thematic analysis embedded within a Framework analysis comparing answers from Sweden and UK. Results: Personal perceptions of risky drinking were formed primarily using experiential and affective judgments, and related to concerns over developing problems with alcohol, losing control, drinking as a coping mechanism, and causing harm to oneself or others. Guidelines were interpreted using experiential judgements, resulting in affective responses, expressed as negative attitudes towards the guidelines in terms of scepticism and denial. Those acknowledging the risk expressed ambivalence, in terms of a struggle for change. Conclusions: Perceptions of risky drinking extend beyond the physical act of consuming alcohol and encompass various contextual factors, affective states, effects of alcohol on the individual, and its impact on social roles and relationships. Risk guidance may not be interpreted as intended, with many who exceed the recommendations do not perceive their behaviour as risky. Understanding perceptions of risk can help support changes in behaviour,

Introduction Alcohol consumption that damages health remains highly prevalent in Sweden despite macrolevel intervention measures such as availability, restrictions and taxation. As understanding of behaviour change develops, there may be an opportunity to enhance individual level interventions by targeting personal dimensions of behaviour, such as underlying motives for drinking alcohol and readiness to change behaviour. This protocol describes a randomised controlled trial aimed at estimating the effectiveness of an intervention tailored to motives and readiness to change. Methods and analysis A three-arm, parallel groups, randomised controlled trial will be used to estimate the effects of a motives and readiness to change tailored intervention. We will use a Bayesian sequential design to decide when to stop recruitment, with target criteria for benefit, harm and futility. Recruitment will be completed via web adverts and social media. Inclusion criteria are being aged 18 or older, having access to a mobile phone and being classified as a risky drinker. Participants allocated to the two intervention groups will receive either a personalised digital intervention or an intervention with enhanced tailoring for motives and readiness to change. The personalised intervention consists of weekly screening, personalised feedback and tools for planning behaviour. The enhanced tailored version will follow the same logic but will contain materials tailored for individuals’ drinking motives and readiness to change. The control group will be redirected to two national websites with information about alcohol and health. Outcome measures are weekly alcohol consumption and monthly heavy drinking episodes, which will be contrasted with regression models and estimated using Bayesian inference. Ethics and dissemination Ethical approval was obtained from the Swedish Ethical Review Authority on 16 April 2024, (Dnr 2024-01630-01). The results of the study will be disseminated in academic journals and research conferences. Trial registration number The trial was preregistered in the ISRCTN Registry on 12 June 2024 (ISRCTN87600318).

Introduction In Sweden and the UK, there is a high prevalence of risky drinking, a pattern of drinking associated with adverse consequences. Drinking motives are a proximal predictor of risky drinking and subsequent consequences, suggesting it may be an apt intervention target. Currently, there is a lack of evidence regarding the applicability of motives for intervention efforts. The current study aims to test if motives-based materials are effective in impacting plans for future drinking and reactivity to alcohol-related cues. A secondary aim is to assess individuals’ perceptions of risky drinking as outlined by health authorities. The results of the study will inform the design of a motives-based digital alcohol intervention. Methods and analysis The study is a three-arm, parallel group, randomised controlled trial. Vignettes will be used to present health information, framed in terms of gains from limiting drinking and losses from excess drinking. Control vignettes will present general health information framed in terms of gains or losses. Proxies for behaviour (intentions and self-efficacy) will be assessed with questionnaire items. A Stroop task will be used to assess reactivity to alcohol cues, and an open-ended item will be used to record perceptions of risky drinking. Outcomes will be contrasted with regression models and estimated using Bayesian inference, while qualitative data will be analysed using thematic analysis within a framework analysis. Ethics and dissemination Ethical approval for the study was waived by the Swedish Ethical Review Authority on 16 December 2023 based on participants being anonymous (Dnr. 2023-06474-01). The results of the study will be disseminated in an academic journal and research conferences while also informing the design of a national digital alcohol intervention. Trial registration number ISRCTN12456514.

Aims: Conditional average treatment effects are often reported in intervention studies, in which assumptions are made regarding how effects are similar across a heterogeneous sample. Nonetheless, differing factors, such as genetics, age, and sex, can impact an intervention’s effect on outcomes. The study aimed to estimate the individualized effects of a digital alcohol intervention among individuals looking online to reduce their drinking. Methods: We used data from a randomized controlled trial (RCT), including 2129 adults from the Swedish general population. The RCT concerned a text message-based alcohol intervention that sought to engender change through increasing knowledge on how to change and instilling confidence in changing behaviour. Outcomes were total weekly alcohol consumption and monthly heavy episodic drinking. Individualized treatment effects were modelled using baseline characteristics (age, gender, alcohol consumption, and psychosocial variables) and engagement with the intervention content. Results: We found evidence that the effects of the digital alcohol intervention were heterogeneous concerning participants’ age, baseline alcohol consumption, confidence, and importance. For heavy episodic drinking, there was evidence that effects were heterogeneous concerning age, sex, and baseline alcohol consumption. Overall, women, older individuals, and heavier drinkers benefitted more from the intervention in terms of effect size. In addition, participants who engaged more with the goal-setting and screening content reported better outcomes. Conclusions: The results highlight how different individuals respond differently to a digital alcohol intervention. This allows insight into who benefits the most and least from the intervention and highlights the potential merit of designing interventions adapted to different individuals’ needs.

Background and Aims: Digital smoking cessation interventions have been shown to be effective in helping individuals achieve prolonged smoking abstinence. Nonetheless, the mechanisms that drive such effects are unclear. The current study aimed to estimate a digital smoking cessation intervention's natural direct and indirect effects. Methods: This secondary analysis of mediated effects uses data from a randomised controlled trial which included participants who smoked at least one cigarette a week, had access to a mobile phone, and were 18 years or older. The comparator was existing smoking cessation support available to all members of the Swedish public. Primary outcomes were prolonged smoking abstinence and point prevalence of smoking abstinence, measured at 3- and 6-months post-randomisation. A counterfactual framework was used to estimate three hypothesised mediators of the intervention's effects: importance, knowledge of how to change (know-how), and confidence. Results: Between 18/09/20 and 16/06/22, 1012 participants were randomised. The intervention led to improved confidence and know-how, which both partially mediated the effects of the digital intervention on smoking abstinence at 3- and 6 months post-randomisation. Conclusions: A digital smoking cessation intervention was found to partially affect smoking abstinence by improving individuals’ confidence in their ability to quit smoking and developing knowledge on how to quit. Face-value single-item mediator measures, lack of blinding, and attrition limit the study. Future studies should address these limitations and assess additional mechanisms mediating intervention effects. Trial registration: ISRCTN13455271.