Person: Swanson, Sonja
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Swanson
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Sonja
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Swanson, Sonja
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Publication Bounding the per-protocol effect in randomized trials: an application to colorectal cancer screening(BioMed Central, 2015) Swanson, Sonja; Holme, Øyvind; Løberg, Magnus; Kalager, Mette; Bretthauer, Michael; Hoff, Geir; Aas, Eline; Hernan, MiguelBackground: The per-protocol effect is the effect that would have been observed in a randomized trial had everybody followed the protocol. Though obtaining a valid point estimate for the per-protocol effect requires assumptions that are unverifiable and often implausible, lower and upper bounds for the per-protocol effect may be estimated under more plausible assumptions. Strategies for obtaining bounds, known as “partial identification” methods, are especially promising in randomized trials. Results: We estimated bounds for the per-protocol effect of colorectal cancer screening in the Norwegian Colorectal Cancer Prevention trial, a randomized trial of one-time sigmoidoscopy screening in 98,792 men and women aged 50–64 years. The screening was not available to the control arm, while approximately two thirds of individuals in the treatment arm attended the screening. Study outcomes included colorectal cancer incidence and mortality over 10 years of follow-up. Without any assumptions, the data alone provide little information about the size of the effect. Under the assumption that randomization had no effect on the outcome except through screening, a point estimate for the risk under no screening and bounds for the risk under screening are achievable. Thus, the 10-year risk difference for colorectal cancer was estimated to be at least −0.6 % but less than 37.0 %. Bounds for the risk difference for colorectal cancer mortality (–0.2 to 37.4 %) and all-cause mortality (–5.1 to 32.6 %) had similar widths. These bounds appear helpful in quantifying the maximum possible effectiveness, but cannot rule out harm. By making further assumptions about the effect in the subpopulation who would not attend screening regardless of their randomization arm, narrower bounds can be achieved. Conclusions: Bounding the per-protocol effect under several sets of assumptions illuminates our reliance on unverifiable assumptions, highlights the range of effect sizes we are most confident in, and can sometimes demonstrate whether to expect certain subpopulations to receive more benefit or harm than others. Trial registration Clinicaltrials.gov identifier NCT00119912 (registered 6 July 2005) Electronic supplementary material The online version of this article (doi:10.1186/s13063-015-1056-8) contains supplementary material, which is available to authorized users.Publication Binge/purge thoughts in nonsuicidal self-injurious adolescents: An ecological momentary analysis(Wiley-Blackwell, 2013) Shingleton, Rebecca; Eddy, Kamryn T.; Keshaviah, Aparna; Franko, Debra L.; Swanson, Sonja; Yu, Jessica S.; Krishna, Meera; Nock, Matthew; Herzog, DavidObjective Adolescents who self-injure often engage in bingeing/purging (BP). Ecological momentary assessment (EMA) has potential to offer insight into the relationship between self-injury and BP. The aims of this study were to examine the frequency and context of BP using EMA in a sample of nonsuicidal self-injurious (NSSI) adolescents. Method Thirty adolescents with a history of NSSI responded to questions regarding self-destructive thoughts/behaviors using a palm-pilot device. Descriptive analyses compared thought/behavior contexts during reports of BP and NSSI thoughts/behaviors (occurring together vs. individually). Results BP thoughts were present in 22 (73%) participants, occurring on 32% of the person-days recorded; 59% of these participants actually engaged in BP behavior. Seventy-nine percent of BP thoughts co-occurred with other self-destructive thoughts. Adolescents were more often with friends/peers than alone or with family when having BP thoughts. Worry and pressure precipitated both BP and NSSI thoughts, but perceived criticism and feelings of rejection/hurt were associated more often with BP thoughts than with NSSI thoughts. Discussion BP thoughts and behaviors were common in this sample, often occurring with other self-destructive thoughts. Future EMA research is needed to address the function of BP symptoms, the contextual variables that increase risk for BP thoughts, and the factors that predict the transition of thoughts into behaviors in adolescents with and without self-injury.Publication Twelve-Month Suicidal Symptoms and Use of Services Among Adolescents: Results From the National Comorbidity Survey(American Psychiatric Publishing, 2012) Husky, Mathilde M.; Olfson, Mark; He, Jian-ping; Nock, Matthew; Swanson, Sonja; Merikangas, Kathleen RiesObjective The study assessed the prevalence of suicidal ideation, suicide plans, and suicide attempts as well as patterns of mental health service use among adolescents. Methods Data came from the National Comorbidity Survey–Adolescent Supplement, a nationally representative sample of 10,123 adolescents aged 13 to 18 years who participated in computer-assisted, face-to-face interviews between February 2001 and January 2004. Prevalences of suicidal thoughts and behaviors in the past year were determined. Past-year use of any mental health treatment and receipt of four or more visits from one provider among youths with suicidal ideation, plans, or attempts were also assessed. Associations were evaluated by using logistic regression. Results During the course of 12 months, 3.6% of adolescents reported suicidal ideation without a plan or attempt, .6% reported a suicide plan without an attempt, and 1.9% made a suicide attempt. Overall, two-thirds of adolescents with suicidal ideation (67.3%) and half of those with a plan (54.4%) or attempt (56.9%) did not have any contact with a mental health specialist in the past year. Different predictors of use of care were identified for each group. Conclusions Adolescent suicidality often is untreated in the United States. Increased outreach efforts to improve treatment access for youths with suicidal ideation and attempts are needed.Publication Communicating causality(Springer Netherlands, 2015) Swanson, Sonja