What to do after smoking relapse? A sequential multiple assignment randomized trial of chronic care smoking treatments

AIM

To compare effects of three post-relapse interventions on smoking abstinence.

DESIGN

Sequential three-phase multiple assignment randomized trial (SMART).

SETTING

Eighteen Wisconsin, USA, primary care clinics.

PARTICIPANTS

A total of 1154 primary care patients (53.6% women, 81.2% White) interested in quitting smoking enrolled from 2015 to 2019; 582 relapsed and were randomized to relapse recovery treatment.

INTERVENTIONS

In phase 1, patients received cessation counseling and 8 weeks nicotine patch. Those who relapsed and agreed were randomized to a phase 2 relapse recovery group: (1) reduction counseling + nicotine mini-lozenges + encouragement to quit starting 1 month post-randomization (preparation); (2) repeated encouragement to quit starting immediately post-randomization (recycling); or (3) advice to call the tobacco quitline (control). The first two groups could opt into phase 3 new quit treatment [8 weeks nicotine patch + mini-lozenges plus randomization to two treatment factors (skill training and supportive counseling) in a 2 × 2 design]. Phase 2 and 3 interventions lasted ≤ 15 months.

MEASUREMENTS

The study was powered to compare each active phase 2 treatment with the control on the primary outcome: biochemically confirmed 7-day point-prevalence abstinence 14 months post initiating phase 2 relapse recovery treatment. Exploratory analyses tested for phase 3 counseling factor effects.

FINDINGS

Neither skill training nor supportive counseling (each on versus off) increased 14-month abstinence rates; skills on versus off 9.3% (14/151) versus 5.2% (8/153), P = 0.19; support on versus off 6.6% (10/152) versus 7.9% (12/152), P = 0.73. Phase 2 preparation did not produce higher 14-month abstinence rates than quitline referral; 3.6% (8/220) versus 2.1% [3/145; risk difference = 1.5%, 95% confidence interval (CI) = -1.8-5.0%, odds ratio (OR) = 1.8, 95% CI = 0.5-6.9]. Recycling, however, produced higher abstinence rates than quitline referral; 6.9% (15/217) versus 2.1% (three of 145; risk difference, 4.8%, 95% CI = 0.7-8.9%, OR = 3.5, 95% CI = 1.0-12.4). Recycling produced greater entry into new quit treatment than preparation: 83.4% (181/217) versus 55.9% (123/220), P < 0.0001.

CONCLUSIONS

Among people interested in quitting smoking, immediate encouragement post-relapse to enter a new round of smoking cessation treatment ('recycling') produced higher probability of abstinence than tobacco quitline referral. Recycling produced higher rates of cessation treatment re-engagement than did preparation/cutting down using more intensive counseling and pharmacotherapy.

Modeling of the Efficiency of the Centrifugal Conical Disk Dispenser of Bulk Materials

Centrifugal disk dispensers are widely used in various tasks of dosing bulk, dispersed materials. The design of the disk depends on the physical and mechanical characteristics of the dosing medium. The work discusses the development of an analytical model of the movement of a material particle along a conical centrifugal disk depending on the kinematic characteristics of the dosing process and the characteristics of the dosing material, as well as experimental confirmation of the theoretical model, which is relevant for the calculation and design of working elements of this type. The obtained system of differential equations is solved using the Runge-Kutta numerical method. Experimental studies were carried out using the method of a planned factorial experiment. The experiment was conducted for three factors at three levels. The feedback criterion was the performance of a centrifugal conical disk dispenser for bulk materials. The disk cone angle was set at 10, 20, and 30°. The disk diameter was 130, 150, and 170 mm, the gap between the disk and the edge of the hopper neck was 6, 8, and 10 mm, and the rotational speed of the conical disk was 0.65, 1.02, and 1.39 rad/s. The dispensing rate of the dispenser ranged from 15 to 770 g/s, depending on the values of the experimental factors. For use in the regression equation of the natural values of the factors, a method of transforming the terms of the equation from coded values to natural ones is provided. The obtained experimental correlation dependencies were checked for reproducibility with Cochrane's test, and the adequacy of the model was checked using Fisher's test. The significance of the coefficients in the correlation equation was evaluated using the Student's t-test. The difference between the experimental data and the results of the theoretical modeling does not exceed 5%. The obtained system of differential equations makes it possible to model the radial velocity of the ascent of bulk material from the conical rotating disk depending on the rotation frequency, disk diameter, and the height of the annular gap between the discharge throat of the hopper and the conical disk. The analytical model enables the modeling of the productivity of the conical dispenser for bulk materials for arbitrary parameters of rotation frequency, disk diameter, and the size of the annular gap between the discharge throat of the hopper and the conical disk.

Optimizing UVC-LED application to improve the shelf life of vacuum-packed refrigerated stored Nile tilapia (Oreochromis niloticus) fillets

Although ultraviolet-C light-emitting diode (UVC-LED) has proven antimicrobial effectiveness doses needed to reach it cause adverse effects on the physicochemical quality of fish, and thus, optimization studies are crucial to boost its industrial application. This study aimed to identify optimal UVC-LED conditions for maximum shelf life extension with the least possible quality changes of refrigerated stored tilapia fillets from a central composite rotatable design (CCRD). UVC-LED powers (1, 1.38, and 1.58 mW/cm2 ) and times (500, 1800, and 2700 s) were set on the CCRD, which generated 11 treatments, including three replicate experiments. Treatments were analyzed for total aerobic psychrotrophic count, lipid oxidation, instrumental color, and texture parameters on days 0, 2, 4, 7, 11, and 14. The UVC-LED affected shelf life and physicochemical parameters in a nonlinear fashion. UVC-LED-treated fish had increased shelf life by 2.80-4.76 days and increase or decrease in lipid oxidation (0.025-0.276 mg of malondialdehyde [MDA]/kg), total color change (∆E = 3.47-9.06), and hardness (1.31-8.51 N) over the refrigerated storage depending on specific UVC-LED conditions applied. The optimal UVC-LED condition was 0.97 mW/cm2 with 2503.6 s (2428.50 mJ/cm2 ), which increased the fillet's shelf life by 2.5-fold (2 days) while maintaining quality closer to the original throughout refrigerated storage, resulting in ∆E < 5, an increase of only 0.05 mg of MDA/kg, and preservation of the decrease in hardness by 3.38 N compared to its control counterparts. Therefore, it represents an eco-friendly technology that can easily scaled industrially to enhance the sustainable fish production chain. PRACTICAL APPLICATION: The high fish perishability is a global concern due to food safety risks and waste generation impacting the environment adversely, especially nowadays, where fish production and consumption have increased, and there are more evident efforts to sustainable production. UVC-LED is an eco-friendly technology with proven antimicrobial effectiveness but doses needed to reach this effect enhance oxidative degradation. Despite that, optimization studies concerning the maximum shelf life extension while retaining the physicochemical quality of refrigerated stored fish are a gap in the literature and a barrier to its industrial application. Our findings are helpful in sustainably enhancing the fish production chain.

Propagation of Sounds through Small Panels Made of Polymer Materials by 3D Printing

To evaluate the sound insulation capacity of small panels made of polymeric materials by 3D printing, a Taguchi L18-type factorial experiment with eight independent variables was designed and materialized. The independent variables were the panel thickness, polymer material type, 3D printing speed, infill percent, infill pattern, layer thickness, frequency, and sound volume. Empirical mathematical models were determined through the mathematical processing of the experimental results using specialized software. These empirical mathematical models highlight the meaning and intensity of the influence exerted by the input factors in the process on the acoustic pressure level of the energy absorbed after the passage of sounds through the small panels manufactured by 3D printing from polylactic acid and polyethylene terephthalate glycol. The factor with the strongest influence was the frequency of the sounds, with a maximum of the sound pressure level for a frequency of 13,000 Hz. A polylactic acid panel between the sound source and the sound-receiving sensor reduces the sound pressure level by about 45% from 95.8 to 65.8 dB. The power function type mathematical model in the case of the energy absorbed by the panel highlights the fact that the highest values of the exponents are those attached to the sound frequency (exponent equal to 1.616) and, respectively, to the thickness of the panel (exponent equal to -0.121).

Supporting Autonomous Motivation for Physical Activity With Chatbots During the COVID-19 Pandemic: Factorial Experiment

BACKGROUND

Although physical activity can mitigate disease trajectories and improve and sustain mental health, many people have become less physically active during the COVID-19 pandemic. Personal information technology, such as activity trackers and chatbots, can technically converse with people and possibly enhance their autonomous motivation to engage in physical activity. The literature on behavior change techniques (BCTs) and self-determination theory (SDT) contains promising insights that can be leveraged in the design of these technologies; however, it remains unclear how this can be achieved.

OBJECTIVE

This study aimed to evaluate the feasibility of a chatbot system that improves the user's autonomous motivation for walking based on BCTs and SDT. First, we aimed to develop and evaluate various versions of a chatbot system based on promising BCTs. Second, we aimed to evaluate whether the use of the system improves the autonomous motivation for walking and the associated factors of need satisfaction. Third, we explored the support for the theoretical mechanism and effectiveness of various BCT implementations.

METHODS

We developed a chatbot system using the mobile apps Telegram (Telegram Messenger Inc) and Google Fit (Google LLC). We implemented 12 versions of this system, which differed in 3 BCTs: goal setting, experimenting, and action planning. We then conducted a feasibility study with 102 participants who used this system over the course of 3 weeks, by conversing with a chatbot and completing questionnaires, capturing their perceived app support, need satisfaction, physical activity levels, and motivation.

RESULTS

The use of the chatbot systems was satisfactory, and on average, its users reported increases in autonomous motivation for walking. The dropout rate was low. Although approximately half of the participants indicated that they would have preferred to interact with a human instead of the chatbot, 46.1% (47/102) of the participants stated that the chatbot helped them become more active, and 42.2% (43/102) of the participants decided to continue using the chatbot for an additional week. Furthermore, the majority thought that a more advanced chatbot could be very helpful. The motivation was associated with the satisfaction of the needs of competence and autonomy, and need satisfaction, in turn, was associated with the perceived system support, providing support for SDT underpinnings. However, no substantial differences were found across different BCT implementations.

CONCLUSIONS

The results provide evidence that chatbot systems are a feasible means to increase autonomous motivation for physical activity. We found support for SDT as a basis for the design, laying a foundation for larger studies to confirm the effectiveness of the selected BCTs within chatbot systems, explore a wider range of BCTs, and help the development of guidelines for the design of interactive technology that helps users achieve long-term health benefits.

Soil water and nutrient availability interactively modify pollinator-mediated directional and correlational selection on floral display

The individual and combined effects of abiotic factors on pollinator-mediated selection on floral traits are not well documented. To examine potential interactive effects of water and nutrient availability on pollinator-mediated selection on three floral display traits of Primula tibetica, we manipulated pollination and nutrient availability in a factorial experiment, conducted at two common garden sites with different soil water content (natural vs addition). We found that both water and nutrient availability affected floral trait expression in P. tibetica and that hand pollination increased seed production most when both nutrient content and water content were high, indicating joint pollen and resource limitation. We documented selection on all floral traits, and pollinators contributed to directional and correlational selection on plant height and number of flowers. Soil water and nutrient availability interactively influenced the strength of both pollinator-mediated directional and correlational selection, with significant selection observed when nutrient or water availability was high, but not when none or both were added. The results suggest that resource limitation constrains the response of P. tibetica to among-individual variation in pollen receipt, that addition of nutrients or water leads to pollinator-mediated selection and that effects of the two abiotic factors are nonadditive.

Effectiveness of an optimized text message and Internet intervention for smoking cessation: A randomized controlled trial

AIMS

To evaluate the effectiveness of a combined internet and text message intervention for smoking cessation compared with an internet intervention alone. The text message intervention was optimized for engagement in an earlier multiphase optimization (MOST) screening phase.

DESIGN

A parallel, two-group, individually randomized clinical trial (RCT) was conducted in a MOST confirming phase. Recruitment spanned December 2018 to March 2019. Follow-up was conducted at 3 and 9 months, beginning March 2019 and ending January 2020.

SETTING

United States: a digital study conducted among new registrants on a free tobacco cessation website.

PARTICIPANTS

Eligible individuals were 618 adult current smokers in the United States, age 18 years or older who signed up for text messages during website registration (67.2% female, 70.4% white).

INTERVENTIONS

The treatment arm (WEB+TXT; n = 311) received access to the website and text messaging. The control arm (WEB; n = 307) received access to the website alone.

MEASUREMENTS

The primary outcome was self-reported 30-day point prevalence abstinence (ppa) at 9 months post-randomization analyzed under intent to treat (ITT), counting non-responders as smoking. Secondary outcomes included 3-month measures of 30-day ppa, intervention engagement and intervention satisfaction.

FINDINGS

Abstinence rates at 9 months were 23.1% among WEB+TXT and 23.2% among WEB (OR = 1.00, 95% CI = 0.69-1.45; P = 0.99). WEB+TXT increased engagement with 5 of 6 interactive features (standardized mean difference (SMD) = 0.26-0.47, all P < 0.001) and repeat website visits (48.7% vs 38.9%, SMD = 0.14, P = 0.02). Satisfaction metrics favored WEB+TXT (satisfied: 96.3% vs 90.5%, SMD = 0.17, P = 0.008; recommend to friend: 95.9% vs 90.1%, SMD = 0.16, P = 0.028).

CONCLUSIONS

A randomized controlled trial found no evidence that a combined internet and text message intervention for smoking cessation compared with an internet intervention alone increased 9-month abstinence rates among adult current smokers in the United States, despite evidence of higher levels of intervention engagement and satisfaction at 3 months.

Evaluating four motivation-phase intervention components for use with primary care patients unwilling to quit smoking: a randomized factorial experiment

AIMS

To assess the effectiveness of intervention components designed to increase quit attempts and promote abstinence in patients initially unwilling to quit smoking.

DESIGN

A four-factor, randomized factorial experiment.

SETTING

Sixteen primary care clinics in southern Wisconsin.

PARTICIPANTS

A total of 577 adults who smoke (60% women, 80% White) recruited during primary care visits who were currently willing to reduce their smoking but unwilling to try to quit. Interventions Four factors contrasted intervention components administered over a 1-year period: (i) nicotine mini-lozenge versus none; (ii) reduction counseling versus none; (iii) behavioral activation (BA) counseling versus none; and (iv) motivational 5Rs counseling versus none. Participants could request cessation treatment at any time.

MEASUREMENTS

The primary outcome was 7-day point-prevalence abstinence at 52 weeks post enrollment; secondary outcomes were point-prevalence abstinence at 26 weeks and making a quit attempt by weeks 26 and 52.

FINDINGS

No abstinence main effects were found but a mini-lozenge × reduction counseling × BA interaction was found at 52 weeks; P = 0.03. Unpacking this interaction showed that the mini-lozenge alone produced the highest abstinence rate (16.7%); combining it with reduction counseling produced an especially low abstinence rate (4.1%). Reduction counseling decreased the likelihood of making a quit attempt by 52 weeks relative to no reduction counseling (P = 0.01).

CONCLUSIONS

Nicotine mini-lozenges may increase smoking abstinence in people initially unwilling to quit smoking, but their effectiveness declines when used with smoking reduction counseling or other behavioral interventions. Reduction counseling decreases the likelihood of making a quit attempt in people initially unwilling to quit smoking.

Applying the Multiphase Optimization Strategy for the Development of Optimized Interventions in Palliative Care

Recent systematic reviews and meta-analyses have reported positive benefit of multicomponent "bundled" palliative care interventions for patients and family caregivers while highlighting limitations in determining key elements and mechanisms of improvement. Traditional research approaches, such as the randomized controlled trial (RCT), typically treat interventions as "bundled" treatment packages, making it difficult to assess definitively which aspects of an intervention can be reduced or replaced or whether there are synergistic or antagonistic interactions between intervention components. Progressing toward palliative care interventions that are effective, efficient, and scalable will require new strategies and novel approaches. One such approach is the Multiphase Optimization Strategy (MOST), a framework informed by engineering principles, that uses a systematic process to empirically identify an intervention comprised of components that positively contribute to desired outcomes under real-life constraints. This article provides a brief overview and application of MOST and factorial trial design in palliative care research, including our insights from conducting a pilot factorial trial of an early palliative care intervention to enhance the decision support skills of advanced cancer family caregivers (Project CASCADE).

The health belief model predicts vaccination intentions against COVID-19: A survey experiment approach

With the COVID‐19 pandemic recognized as a major threat to human health is of paramount importance to improve the vaccination uptake of the future COVID‐19 vaccine. The study extended the health belief model (HBM) using insights from trait theory and events systems theory, to examine the role of beliefs in predicting intentions to be vaccinated against COVID‐19, when a vaccine becomes available. Employees from Greece (N = 1006) participated from October 1 to November 5, 2020, in an anonymous online factorial survey experiment. Measures of dispositional optimism, faith in intuition, risk‐taking propensity, and acquiring resources mindset were included as individual difference variables. Multilevel modeling techniques were used for data analyses. Components of HBM had significant effects on intentions to vaccinate. Two‐way interactions between severity and susceptibility beliefs and three‐way interaction among perceived severity, susceptibility, and perceived benefits were detected. In line with the events systems theory, a critical event moderated beliefs' effects on intention to vaccinate. Acquiring resources mindset emerged as important individual difference that positively related to intentions. The model explained 59 per cent of the variance in vaccination intentions. The study highlighted interaction effects among the HBM components and how critical events may moderate belief effects.

LIBERTI: A SMART study in plastic surgery

BACKGROUND/AIMS

Laser treatment of burns scars is considered by some providers to be standard of care. However, there is little evidence-based research as to the true benefit. A number of factors hinder evaluation of the benefit of laser treatment. These include significant heterogeneity in patient response and possible delayed effects from the laser treatment. Moreover, laser treatments are often provided sequentially using different types of equipment and settings, so there are effectively a large number of overall treatment options that need to be compared. We propose a trial capable of coping with these issues and that also attempts to take advantage of the heterogeneous response in order to estimate optimal treatment plans personalized to each individual patient. It will be the first large-scale randomized trial to compare the effectiveness of laser treatments for burns scars and, to our knowledge, the very first example of the utility of a Sequential Multiple Assignment Randomized Trial in plastic surgery.

METHODS

We propose using a Sequential Multiple Assignment Randomized Trial design to investigate the effect of various permutations of laser treatment on hypertrophic burn scars. We will compare and test hypotheses regarding laser treatment effects at a general population level. Simultaneously, we hope to use the data generated to discover possible beneficial personalized treatment plans, tailored to individual patient characteristics.

RESULTS

We show that the proposed trial has good power to detect laser treatment effect at the overall population level, despite comparing a large number of treatment combinations. The trial will simultaneously provide high-quality data appropriate for estimating precision-medicine treatment rules. We detail population-level comparisons of interest and corresponding sample size calculations. We provide simulations to suggest the power of the trial to detect laser effect and also the possible benefits of personalization of laser treatment to individual characteristics.

CONCLUSION

We propose, to our knowledge, the first use of a Sequential Multiple Assignment Randomized Trial in surgery. The trial is rigorously designed so that it is reasonably straightforward to implement and powered to answer general overall questions of interest. The trial is also designed to provide data that are suitable for the estimation of beneficial precision-medicine treatment rules that depend both on individual patient characteristics and on-going real-time patient response to treatment.

Food provisioning alters infection dynamics in populations of a wild rodent

While pathogens are often assumed to limit the growth of wildlife populations, experimental evidence for their effects is rare. A lack of food resources has been suggested to enhance the negative effects of pathogen infection on host populations, but this theory has received little investigation. We conducted a replicated two-factor enclosure experiment, with introduction of the bacterium Bordetella bronchiseptica and food supplementation, to evaluate the individual and interactive effects of pathogen infection and food availability on vole populations during a boreal winter. We show that prior to bacteria introduction, vole populations were limited by food availability. Bordetella bronchiseptica introduction then reduced population growth and abundance, but contrary to predictions, primarily in food supplemented populations. Infection prevalence and pathological changes in vole lungs were most common in food supplemented populations, and are likely to have resulted from increased congregation and bacteria transmission around feeding stations. Bordetella bronchiseptica-infected lungs often showed protozoan co-infection (consistent with Hepatozoon erhardovae), together with more severe inflammatory changes. Using a multidisciplinary approach, this study demonstrates a complex picture of interactions and underlying mechanisms, leading to population-level effects. Our results highlight the potential for food provisioning to markedly influence disease processes in wildlife mammal populations.

Comparative effectiveness of motivation phase intervention components for use with smokers unwilling to quit: a factorial screening experiment

AIMS

To screen promising intervention components designed to reduce smoking and promote abstinence in smokers initially unwilling to quit.

DESIGN

A balanced, four-factor, randomized factorial experiment.

SETTING

Eleven primary care clinics in southern Wisconsin, USA.

PARTICIPANTS

A total of 517 adult smokers (63.4% women, 91.1% white) recruited during primary care visits who were willing to reduce their smoking but not quit.

INTERVENTIONS

Four factors contrasted intervention components designed to reduce smoking and promote abstinence: (1) nicotine patch versus none; (2) nicotine gum versus none; (3) motivational interviewing (MI) versus none; and (4) behavioral reduction counseling (BR) versus none. Participants could request cessation treatment at any point during the study.

MEASUREMENTS

The primary outcome was percentage change in cigarettes smoked per day at 26 weeks post-study enrollment; the secondary outcomes were percentage change at 12 weeks and point-prevalence abstinence at 12 and 26 weeks post-study enrollment.

FINDINGS

There were few main effects, but a significant four-way interaction at 26 weeks post-study enrollment (P = 0.01, β = 0.12) revealed relatively large smoking reductions by two component combinations: nicotine gum combined with BR and BR combined with MI. Further, BR improved 12-week abstinence rates (P = 0.04), and nicotine gum, when used without MI, increased 26-week abstinence after a subsequent aided quit attempt (P = 0.01).

CONCLUSIONS

Motivation-phase nicotine gum and behavioral reduction counseling are promising intervention components for smokers who are initially unwilling to quit.

Comparative effectiveness of intervention components for producing long-term abstinence from smoking: a factorial screening experiment

AIMS

To identify promising intervention components that help smokers attain and maintain abstinence during a quit attempt.

DESIGN

A 2 × 2 × 2 × 2 × 2 randomized factorial experiment.

SETTING

Eleven primary care clinics in Wisconsin, USA.

PARTICIPANTS

A total of 544 smokers (59% women, 86% white) recruited during primary care visits and motivated to quit.

INTERVENTIONS

Five intervention components designed to help smokers attain and maintain abstinence: (1) extended medication (26 versus 8 weeks of nicotine patch + nicotine gum); (2) maintenance (phone) counseling versus none; (3) medication adherence counseling versus none; (4) automated (medication) adherence calls versus none; and (5) electronic medication monitoring with feedback and counseling versus electronic medication monitoring alone.

MEASUREMENTS

The primary outcome was 7-day self-reported point-prevalence abstinence 1 year after the target quit day.

FINDINGS

Only extended medication produced a main effect. Twenty-six versus 8 weeks of medication improved point-prevalence abstinence rates (43 versus 34% at 6 months; 34 versus 27% at 1 year; P = 0.01 for both). There were four interaction effects at 1 year, showing that an intervention component's effectiveness depended upon the components with which it was combined.

CONCLUSIONS

Twenty-six weeks of nicotine patch + nicotine gum (versus 8 weeks) and maintenance counseling provided by phone are promising intervention components for the cessation and maintenance phases of smoking treatment.

Identifying effective intervention components for smoking cessation: a factorial screening experiment

AIMS

To identify promising intervention components intended to help smokers to attain and maintain abstinence in their quit smoking attempts.

DESIGN

A fully crossed, six-factor randomized fractional factorial experiment.

SETTING

Eleven primary care clinics in southern Wisconsin, USA.

PARTICIPANTS

A total of 637 adult smokers (55% women, 88% white) motivated to quit smoking who visited primary care clinics.

INTERVENTIONS

Six intervention components designed to prepare smokers to quit, and achieve and maintain abstinence (i.e. for the preparation, cessation and maintenance phases of smoking treatment): (1) preparation nicotine patch versus none; (2) preparation nicotine gum versus none; (3) preparation counseling versus none; (4) intensive cessation in-person counseling versus minimal; (5) intensive cessation telephone counseling versus minimal; and (6) 16 versus 8 weeks of combination nicotine replacement therapy (nicotine patch  +  nicotine gum).

MEASUREMENTS

Seven-day self-reported point-prevalence abstinence at 16 weeks.

FINDINGS

Preparation counseling significantly improved week 16 abstinence rates (P = .04), while both forms of preparation nicotine replacement therapy interacted synergistically with intensive cessation in-person counseling (P < 0.05). Conversely, intensive cessation phone counseling and intensive cessation in-person counseling interacted antagonistically (P < 0.05)-these components produced higher abstinence rates by themselves than in combination.

CONCLUSIONS

Preparation counseling and the combination of intensive cessation in-person counseling with preparation nicotine gum or patch are promising intervention components for smoking and should be evaluated as an integrated treatment package.

Enhancing the effectiveness of smoking treatment research: conceptual bases and progress

BACKGROUND AND AIMS

A chronic care strategy could potentially enhance the reach and effectiveness of smoking treatment by providing effective interventions for all smokers, including those who are initially unwilling to quit. This paper describes the conceptual bases of a National Cancer Institute-funded research program designed to develop an optimized, comprehensive, chronic care smoking treatment.

METHODS

This research is grounded in three methodological approaches: (1) the Phase-Based Model, which guides the selection of intervention components to be experimentally evaluated for the different phases of smoking treatment (motivation, preparation, cessation, and maintenance); (2) the Multiphase Optimization Strategy (MOST), which guides the screening of intervention components via efficient experimental designs and, ultimately, the assembly of promising components into an optimized treatment package; and (3) pragmatic research methods, such as electronic health record recruitment, that facilitate the efficient translation of research findings into clinical practice. Using this foundation and working in primary care clinics, we conducted three factorial experiments (reported in three accompanying papers) to screen 15 motivation, preparation, cessation and maintenance phase intervention components for possible inclusion in a chronic care smoking treatment program.

RESULTS

This research identified intervention components with relatively strong evidence of effectiveness at particular phases of smoking treatment and it demonstrated the efficiency of the MOST approach in terms both of the number of intervention components tested and of the richness of the information yielded.

CONCLUSIONS

A new, synthesized research approach efficiently evaluates multiple intervention components to identify promising components for every phase of smoking treatment. Many intervention components interact with one another, supporting the use of factorial experiments in smoking treatment development.

Factorial experiments: efficient tools for evaluation of intervention components

BACKGROUND

An understanding of the individual and combined effects of a set of intervention components is important for moving the science of preventive medicine interventions forward. This understanding can often be achieved in an efficient and economical way via a factorial experiment, in which two or more independent variables are manipulated. The factorial experiment is a complement to the RCT; the two designs address different research questions.

PURPOSE

To offer an introduction to factorial experiments aimed at investigators trained primarily in the RCT.

METHODS

The factorial experiment is compared and contrasted with other experimental designs used commonly in intervention science to highlight where each is most efficient and appropriate.

RESULTS

Several points are made: factorial experiments make very efficient use of experimental subjects when the data are properly analyzed; a factorial experiment can have excellent statistical power even if it has relatively few subjects per experimental condition; and when conducting research to select components for inclusion in a multicomponent intervention, interactions should be studied rather than avoided.

CONCLUSIONS

Investigators in preventive medicine and related areas should begin considering factorial experiments alongside other approaches. Experimental designs should be chosen from a resource management perspective, which states that the best experimental design is the one that provides the greatest scientific benefit without exceeding available resources.

An additional cause of health care disparities: the variable clinical decisions of primary care doctors

RATIONALE, AIMS AND OBJECTIVES

Decades of work on health disparities have culminated in identification of three contributors to variability in diagnosis and management of disease: (i) patient attributes; (ii) doctor's characteristics; and (iii) organizational factors. Understanding the relative influence of different contributors to variability in diagnosis and management of diabetes is important to improving quality and reducing disparities. This study was designed to examine the influence of patient, provider and organizational factors on the diagnosis and management of a major chronic disease - diabetes.

METHOD

A factorial experiment using video vignettes was conducted among n = 192 primary care doctors. Doctors were interviewed after viewing vignettes of (1) a 'patient' with symptoms strongly suggestive of diabetes and (2) an already diagnosed diabetes 'patient' with emerging peripheral neuropathy.

RESULTS

A total of 60.9% of doctors identified diabetes as the correct diagnosis, with significant variations depending on the patients' race/ethnicity. Many doctors offered competing diagnoses with high levels of certainty. For the 'patient' with emerging peripheral neuropathy, 42.2% of doctors would do all essential components of a foot examination, while 21.9% would do none.

CONCLUSIONS

That half of all diabetes in the United States remains undiagnosed is unsurprising given only 60.9% of doctors would diagnose it when the condition is strongly suggested, and nearly one-quarter suspecting diabetes would not order tests necessary to confirm it. The diagnosis of diabetes is significantly influenced by a patient's race/ethnicity, and clinical management (specifically for foot neuropathy) is influenced by patient socio-economic status (SES), doctor's gender and access to clinical guidelines.