Integrating Clinical Practice Guidelines for Smoking Cessation Into Mental Health Care for Veterans With Posttraumatic Stress Disorder

Integrating Clinical Practice Guidelines for Smoking Cessation Into Mental Health Care for Veterans With Posttraumatic Stress Disorder

CSP #519 - Integrating Practice Guidelines for Smoking Cessation Into Mental Health Care for PTSD (SCP)

The primary study objective is to conduct a prospective, randomized controlled clinical trial that compares the effectiveness of two approaches for delivering smoking cessation treatment for veterans with posttraumatic stress disorder (PTSD). An approach where smoking cessation treatment is integrated into mental health care for PTSD and delivered by mental health providers (experimental condition) will be compared to specialized smoking cessation clinic referral (VA's usual standard of care). Secondary study objectives are to (a) compare the cost outcomes and cost-effectiveness of IC versus USC, (b) identify treatment process variables that explain (mediate) observed differences in smoking abstinence rates for the two study conditions, and (c) determine whether cessation from smoking is associated with worsening of symptoms of PTSD and/or depression.

Intervention: The research will test the effectiveness of integrating evidence-based, efficacious treatments for tobacco use disorder into mental health care for patients with chronic PTSD. Two different methods for delivering smoking cessation treatment will be compared in a randomized, controlled clinical effectiveness trial conducted at four Department of Veterans Affairs (VA) medical centers. Smokers undergoing mental health care for PTSD who want to quit smoking will be randomly assigned to either (1) guideline-concordant smoking cessation treatment integrated within ongoing mental health care for PTSD, and delivered by mental health providers (Integrated Care (IC), experimental condition), or (2) specialized smoking cessation treatment, delivered separately from PTSD treatment by a smoking cessation clinic (Usual Standard of Care (USC), comparison condition). Primary Hypothesis: IC will be more effective than USC on measures of smoking-related clinical outcomes. Secondary Hypothesis: The following treatment process variables will predict smoking abstinence at 12-months post randomization: (a) number of smoking cessation treatment sessions received, (b) type and duration of protocol medications prescribed by providers (bupropion, transdermal nicotine patch, and nicotine gum), (c) degree of subjects' compliance with prescribed protocol medication, and (d) number of quit attempts marked by abstinence of 7 days or more. Treatment process variables that predict smoking abstinence will be present to a significantly greater degree in IC than USC. Primary Outcomes: The primary outcome measure will be the point-prevalence of smoking abstinence by self-report for the 7 days prior to assessments, obtained at months 3, 6, 9, and 12 following randomization to study conditions. Verification of smoking abstinence will be obtained by CO readings (abstinence < 10 ppm) obtained at each assessment interval. Salivary cotinine levels (abstinence < 20 ng/ml) will be measured to verify abstinence at months 9 and 12 only, as subjects may still be using nicotine replacement medicines at earlier assessment intervals, confounding cotinine assays. Study Abstract: Individuals with posttraumatic stress disorder (PTSD) are far more likely to smoke than those without mental illness and they smoke more heavily. Tobacco use likely contributes to the heightened overall mortality and specific risks for smoking related diseases among veterans with PTSD and commonly co-occurring mental disorders. Symptoms of PTSD and associated mental disorders are linked to the maintenance of tobacco dependence, premature dropout from smoking cessation treatment, and relapse to smoking following quit attempts. Many efficacious tobacco use treatments exist, but a number of barriers limit the effectiveness of current methods for delivering these treatments in VA health care settings, particularly for the mentally ill. Novel approaches to smoking cessation for individuals with PTSD are needed to circumvent these barriers by integrating evidence-based tobacco use treatment into ongoing mental health care. The research proposed here will test the effectiveness of integrating evidence-based treatment for nicotine dependence into mental health care for patients with chronic posttraumatic stress disorder (PTSD). Two different methods for delivering smoking cessation treatment will be compared in a prospective, randomized controlled clinical effectiveness trial conducted at four Department of Veterans Affairs (VA) medical centers. Smokers undergoing mental health care for PTSD (n=440) will be randomly assigned to either: (1) practice guideline-concordant smoking cessation treatment that is integrated within ongoing mental health care for PTSD and delivered by mental health providers (Integrated Care [IC]) or 2) smoking cessation treatment delivered separately from PTSD treatment by smoking cessation specialists (Usual Standard of Care [USC]). Specific aims of the proposed investigation are (1) to demonstrate that IC is more effective than USC in reducing smoking in psychiatric patients with PTSD and (2) to demonstrate that a number of treatment process variables, including the amount or dose of intervention and patient-specific factors, predict abstinence from tobacco use in smokers with PTSD. Intent-to-treat analyses and analyses for treatment completers will be conducted, using a Generalized Estimating Equations approach. If the study hypothesis is confirmed, system-wide implementation of the experimental intervention (IC) for veterans with PTSD would double the number of patients who stop smoking compared to the usual standard of care for tobacco use disorder. Study findings may have implications for integrating smoking cessation treatment into mental health care for patients with disorders other than PTSD.

addictive disorders, clinical trial, cost effectiveness, mental health, military or environmental exposure, multi-site trial, nicotine, nicotine replacement, post traumatic stress, post traumatic stress disorder, psychiatric, psychological, PTSD, smoking cessation, smoking cessation medications, substance abuse

Per standard of care, patients are referred to a smoking cessation clinic for their smoking cessation therapy.

Patients interested in quitting smoking are referred to a separate smoking cessation clinic, per standard of care.

The primary outcome measure was 12-month bio-verified prolonged abstinence from tobacco between 6 and 18 months postrandomization. Prolonged abstinence excluded tobacco use before 6 months postrandomization. Prolonged abstinence defined non-abstinence as 1) smoking for 7 consecutive days or at least once a week for 2 consecutive weeks, or 2) using non-cigarette tobacco for 7 consecutive days or at least once a week for 2 consecutive weeks. Self-reported prolonged abstinence was verified by exhaled CO ≤ 8ppm and urine cotinine <100 ng/mL cotinine equivalents at the 9-18 month visits. If CO or cotinine was missing, a single measure was used for verification. If both CO and cotinine were missing at any visit between 9 and 15 months, patients reporting prolonged abstinence were considered abstinent if all other available bioverification data confirmed abstinence. Patients who lacked CO and cotinine readings at 18 months or failed to attend the 18 month visit were considered nonabstinent.

A secondary outcome was self-reported 1-year prolonged abstinence between 6 and 18 months post-randomization. Prolonged abstinence excluded tobacco use prior to 6 months post-randomization to allow for initial treatment episode completion and recovery from early relapses. Prolonged abstinence defined non-abstinence as: 1) smoking for 7 consecutive days or at least once a week for 2 consecutive weeks, or 2) using non-cigarette tobacco for 7 consecutive days or at least once a week for 2 consecutive weeks.

Severity of PTSD was a predetermined secondary outcome. One of the measurements for this was CAPS at 18 months. The range is 0-136; five rationally derived severity score ranges for interpreting CAPS total score have been proposed and are as follows: 0-19 = asymptomatic/few symptoms, 20-39 = mild PTSD/subthreshold, 40-59 = moderate PTSD/threshold, 60-79 = severe PTSD symptomatology, and >80 = extreme PTSD symptomology. A rationally derived 15-point change in CAPS total severity score has been proposed as a marker of clinically significant change. The above severity ranges and 15-point marker are preliminary (Frank W. Weathers et. al., "Clinician-administered PTSD Scale: A Review of the First Ten Years of Research", Depression and Anxiety 13: 132-156 (2001)). The results are reported in mean change from baseline.

Severity of PTSD was a predetermined secondary outcome. One of the measurements for this was PTSD Checklist (range, 17-85; scores of greater or equal to 50 indicate a PTSD diagnosis) at every assessment. The results are reported as the mean change from baseline for the 3 month assessment.

Severity of PTSD was a predetermined secondary outcome. One of the measurements for this was PTSD Checklist (range, 17-85; scores of greater or equal to 50 indicate a PTSD diagnosis) at every assessment. The results are reported as the mean change from baseline for the 6 month assessment.

Severity of PTSD was a predetermined secondary outcome. One of the measurements for this was PTSD Checklist (range, 17-85; scores of greater or equal to 50 indicate a PTSD diagnosis) at every assessment. The results are reported as the mean change from baseline for the 9 month assessment.

Severity of PTSD was a predetermined secondary outcome. One of the measurements for this was PTSD Checklist (range, 17-85; scores of greater or equal to 50 indicate a PTSD diagnosis) at every assessment. The results are reported as the mean change from baseline for the 12 month assessment.

Severity of PTSD was a predetermined secondary outcome. One of the measurements for this was PTSD Checklist (range, 17-85; scores of greater or equal to 50 indicate a PTSD diagnosis) at every assessment. The results are reported as the mean change from baseline for the 15 month assessment.

Severity of PTSD was a predetermined secondary outcome. One of the measurements for this was PTSD Checklist (range, 17-85; scores of greater or equal to 50 indicate a PTSD diagnosis) at every assessment. The results are reported as the mean change from baseline for the 18 month assessment.

The Patient Health Questionnaire 9 (PHQ-9; range, 0-27; scores of 10-14, 15-19, and greater than or equal to 20 indicate mild, moderate, and severe depression,respectively) measured depression at every assessment. The results are reported as the mean change from baseline for the 3 month assessment.

The Patient Health Questionnaire 9 (PHQ-9; range, 0-27; scores of 10-14, 15-19, and greater than or equal to 20 indicate mild, moderate, and severe depression,respectively) measured depression at every assessment. The results are reported as the mean change from baseline for the 6 month assessment.

The Patient Health Questionnaire 9 (PHQ-9; range, 0-27; scores of 10-14, 15-19, and greater than or equal to 20 indicate mild, moderate, and severe depression,respectively) measured depression at every assessment. The results are reported as the mean change from baseline for the 9 month assessment.

The Patient Health Questionnaire 9 (PHQ-9; range, 0-27; scores of 10-14, 15-19, and greater than or equal to 20 indicate mild, moderate, and severe depression,respectively) measured depression at every assessment. The results are reported as the mean change from baseline for the 12 month assessment.

The Patient Health Questionnaire 9 (PHQ-9; range, 0-27; scores of 10-14, 15-19, and greater than or equal to 20 indicate mild, moderate, and severe depression,respectively) measured depression at every assessment. The results are reported as the mean change from baseline for the 15 month assessment.

The Patient Health Questionnaire 9 (PHQ-9; range, 0-27; scores of 10-14, 15-19, and greater than or equal to 20 indicate mild, moderate, and severe depression,respectively) measured depression at every assessment. The results are reported as the mean change from baseline for the 18 month assessment.

Predetermined secondary smoking outcomes included 7- and 30-day point prevalence abstinence at each assessment, where abstinence was defined as no tobacco use in the prior 7 or 30 days, respectively. Self-reported point prevalence abstinence was determined for all patients, with patients not completing a visit presumed to be nonabstinent.

Predetermined secondary smoking outcomes included 7- and 30-day point prevalence abstinence at each assessment, where abstinence was defined as no tobacco use in the prior 7 or 30 days, respectively. Self-reported point prevalence abstinence was determined for all patients, with patients not completing a visit presumed to be nonabstinent.

Predetermined secondary smoking outcomes included 7- and 30-day point prevalence abstinence at each assessment, where abstinence was defined as no tobacco use in the prior 7 or 30 days, respectively. Self-reported point prevalence abstinence was determined for all patients, with patients not completing a visit presumed to be nonabstinent.

Predetermined secondary smoking outcomes included 7- and 30-day point prevalence abstinence at each assessment, where abstinence was defined as no tobacco use in the prior 7 or 30 days, respectively. Self-reported point prevalence abstinence was determined for all patients, with patients not completing a visit presumed to be nonabstinent.

Predetermined secondary smoking outcomes included 7- and 30-day point prevalence abstinence at each assessment, where abstinence was defined as no tobacco use in the prior 7 or 30 days, respectively. Self-reported point prevalence abstinence was determined for all patients, with patients not completing a visit presumed to be nonabstinent.

Predetermined secondary smoking outcomes included 7- and 30-day point prevalence abstinence at each assessment, where abstinence was defined as no tobacco use in the prior 7 or 30 days, respectively. Self-reported point prevalence abstinence was determined for all patients, with patients not completing a visit presumed to be nonabstinent.

Predetermined secondary smoking outcomes included 7- and 30-day point prevalence abstinence at each assessment, where abstinence was defined as no tobacco use in the prior 7 or 30 days, respectively. Self-reported point prevalence abstinence was determined for all patients, with patients not completing a visit presumed to be nonabstinent. Exhaled carbon monoxide (CO) was obtained at every in person assessment. Urine cotinine levels, using Accutest® NicAlert™ test strips, were ascertained at assessments when patients self-reported no use of tobacco or nicotine replacement therapy in the prior 7 days. Laboratory assays of urine cotinine were obtained when self-reported abstinence disagreed with NicAlert™ results. If bioverification data were missing or did not confirm abstinence, patients were considered nonabstinent at that visit.

Predetermined secondary smoking outcomes included 7- and 30-day point prevalence abstinence at each assessment, where abstinence was defined as no tobacco use in the prior 7 or 30 days, respectively. Self-reported point prevalence abstinence was determined for all patients, with patients not completing a visit presumed to be nonabstinent. Exhaled carbon monoxide (CO) was obtained at every in person assessment. Urine cotinine levels, using Accutest® NicAlert™ test strips, were ascertained at assessments when patients self-reported no use of tobacco or nicotine replacement therapy in the prior 7 days. Laboratory assays of urine cotinine were obtained when self-reported abstinence disagreed with NicAlert™ results. If bioverification data were missing or did not confirm abstinence, patients were considered nonabstinent at that visit.

Predetermined secondary smoking outcomes included 7- and 30-day point prevalence abstinence at each assessment, where abstinence was defined as no tobacco use in the prior 7 or 30 days, respectively. Self-reported point prevalence abstinence was determined for all patients, with patients not completing a visit presumed to be nonabstinent. Exhaled carbon monoxide (CO) was obtained at every in person assessment. Urine cotinine levels, using Accutest® NicAlert™ test strips, were ascertained at assessments when patients self-reported no use of tobacco or nicotine replacement therapy in the prior 7 days. Laboratory assays of urine cotinine were obtained when self-reported abstinence disagreed with NicAlert™ results. If bioverification data were missing or did not confirm abstinence, patients were considered nonabstinent at that visit.

Predetermined secondary smoking outcomes included 7- and 30-day point prevalence abstinence at each assessment, where abstinence was defined as no tobacco use in the prior 7 or 30 days, respectively. Self-reported point prevalence abstinence was determined for all patients, with patients not completing a visit presumed to be nonabstinent. Exhaled carbon monoxide (CO) was obtained at every in person assessment. Urine cotinine levels, using Accutest® NicAlert™ test strips, were ascertained at assessments when patients self-reported no use of tobacco or nicotine replacement therapy in the prior 7 days. Laboratory assays of urine cotinine were obtained when self-reported abstinence disagreed with NicAlert™ results. If bioverification data were missing or did not confirm abstinence, patients were considered nonabstinent at that visit.

Predetermined secondary smoking outcomes included 7- and 30-day point prevalence abstinence at each assessment, where abstinence was defined as no tobacco use in the prior 7 or 30 days, respectively. Self-reported point prevalence abstinence was determined for all patients, with patients not completing a visit presumed to be nonabstinent. Exhaled carbon monoxide (CO) was obtained at every in person assessment. Urine cotinine levels, using Accutest® NicAlert™ test strips, were ascertained at assessments when patients self-reported no use of tobacco or nicotine replacement therapy in the prior 7 days. Laboratory assays of urine cotinine were obtained when self-reported abstinence disagreed with NicAlert™ results. If bioverification data were missing or did not confirm abstinence, patients were considered nonabstinent at that visit.

Predetermined secondary smoking outcomes included 7- and 30-day point prevalence abstinence at each assessment, where abstinence was defined as no tobacco use in the prior 7 or 30 days, respectively. Self-reported point prevalence abstinence was determined for all patients, with patients not completing a visit presumed to be nonabstinent. Exhaled carbon monoxide (CO) was obtained at every in person assessment. Urine cotinine levels, using Accutest® NicAlert™ test strips, were ascertained at assessments when patients self-reported no use of tobacco or nicotine replacement therapy in the prior 7 days. Laboratory assays of urine cotinine were obtained when self-reported abstinence disagreed with NicAlert™ results. If bioverification data were missing or did not confirm abstinence, patients were considered nonabstinent at that visit.

Predetermined secondary smoking outcomes included 7- and 30-day point prevalence abstinence at each assessment, where abstinence was defined as no tobacco use in the prior 7 or 30 days, respectively. Self-reported point prevalence abstinence was determined for all patients, with patients not completing a visit presumed to be nonabstinent.

Predetermined secondary smoking outcomes included 7- and 30-day point prevalence abstinence at each assessment, where abstinence was defined as no tobacco use in the prior 7 or 30 days, respectively. Self-reported point prevalence abstinence was determined for all patients, with patients not completing a visit presumed to be nonabstinent.

Predetermined secondary smoking outcomes included 7- and 30-day point prevalence abstinence at each assessment, where abstinence was defined as no tobacco use in the prior 7 or 30 days, respectively. Self-reported point prevalence abstinence was determined for all patients, with patients not completing a visit presumed to be nonabstinent.

Predetermined secondary smoking outcomes included 7- and 30-day point prevalence abstinence at each assessment, where abstinence was defined as no tobacco use in the prior 7 or 30 days, respectively. Self-reported point prevalence abstinence was determined for all patients, with patients not completing a visit presumed to be nonabstinent.

Predetermined secondary smoking outcomes included 7- and 30-day point prevalence abstinence at each assessment, where abstinence was defined as no tobacco use in the prior 7 or 30 days, respectively. Self-reported point prevalence abstinence was determined for all patients, with patients not completing a visit presumed to be nonabstinent.

Predetermined secondary smoking outcomes included 7- and 30-day point prevalence abstinence at each assessment, where abstinence was defined as no tobacco use in the prior 7 or 30 days, respectively. Self-reported point prevalence abstinence was determined for all patients, with patients not completing a visit presumed to be nonabstinent.

Predetermined secondary smoking outcomes included 7- and 30-day point prevalence abstinence at each assessment, where abstinence was defined as no tobacco use in the prior 7 or 30 days, respectively. Self-reported point prevalence abstinence was determined for all patients, with patients not completing a visit presumed to be nonabstinent. Exhaled carbon monoxide (CO) was obtained at every in person assessment. Urine cotinine levels, using Accutest® NicAlert™ test strips, were ascertained at assessments when patients self-reported no use of tobacco or nicotine replacement therapy in the prior 7 days. Laboratory assays of urine cotinine were obtained when self-reported abstinence disagreed with NicAlert™ results. If bioverification data were missing or did not confirm abstinence, patients were considered nonabstinent at that visit.

Predetermined secondary smoking outcomes included 7- and 30-day point prevalence abstinence at each assessment, where abstinence was defined as no tobacco use in the prior 7 or 30 days, respectively. Self-reported point prevalence abstinence was determined for all patients, with patients not completing a visit presumed to be nonabstinent. Exhaled carbon monoxide (CO) was obtained at every in person assessment. Urine cotinine levels, using Accutest® NicAlert™ test strips, were ascertained at assessments when patients self-reported no use of tobacco or nicotine replacement therapy in the prior 7 days. Laboratory assays of urine cotinine were obtained when self-reported abstinence disagreed with NicAlert™ results. If bioverification data were missing or did not confirm abstinence, patients were considered nonabstinent at that visit.

Predetermined secondary smoking outcomes included 7- and 30-day point prevalence abstinence at each assessment, where abstinence was defined as no tobacco use in the prior 7 or 30 days, respectively. Self-reported point prevalence abstinence was determined for all patients, with patients not completing a visit presumed to be nonabstinent. Exhaled carbon monoxide (CO) was obtained at every in person assessment. Urine cotinine levels, using Accutest® NicAlert™ test strips, were ascertained at assessments when patients self-reported no use of tobacco or nicotine replacement therapy in the prior 7 days. Laboratory assays of urine cotinine were obtained when self-reported abstinence disagreed with NicAlert™ results. If bioverification data were missing or did not confirm abstinence, patients were considered nonabstinent at that visit.

Predetermined secondary smoking outcomes included 7- and 30-day point prevalence abstinence at each assessment, where abstinence was defined as no tobacco use in the prior 7 or 30 days, respectively. Self-reported point prevalence abstinence was determined for all patients, with patients not completing a visit presumed to be nonabstinent. Exhaled carbon monoxide (CO) was obtained at every in person assessment. Urine cotinine levels, using Accutest® NicAlert™ test strips, were ascertained at assessments when patients self-reported no use of tobacco or nicotine replacement therapy in the prior 7 days. Laboratory assays of urine cotinine were obtained when self-reported abstinence disagreed with NicAlert™ results. If bioverification data were missing or did not confirm abstinence, patients were considered nonabstinent at that visit.

Predetermined secondary smoking outcomes included 7- and 30-day point prevalence abstinence at each assessment, where abstinence was defined as no tobacco use in the prior 7 or 30 days, respectively. Self-reported point prevalence abstinence was determined for all patients, with patients not completing a visit presumed to be nonabstinent. Exhaled carbon monoxide (CO) was obtained at every in person assessment. Urine cotinine levels, using Accutest® NicAlert™ test strips, were ascertained at assessments when patients self-reported no use of tobacco or nicotine replacement therapy in the prior 7 days. Laboratory assays of urine cotinine were obtained when self-reported abstinence disagreed with NicAlert™ results. If bioverification data were missing or did not confirm abstinence, patients were considered nonabstinent at that visit.

Predetermined secondary smoking outcomes included 7- and 30-day point prevalence abstinence at each assessment, where abstinence was defined as no tobacco use in the prior 7 or 30 days, respectively. Self-reported point prevalence abstinence was determined for all patients, with patients not completing a visit presumed to be nonabstinent. Exhaled carbon monoxide (CO) was obtained at every in person assessment. Urine cotinine levels, using Accutest® NicAlert™ test strips, were ascertained at assessments when patients self-reported no use of tobacco or nicotine replacement therapy in the prior 7 days. Laboratory assays of urine cotinine were obtained when self-reported abstinence disagreed with NicAlert™ results. If bioverification data were missing or did not confirm abstinence, patients were considered nonabstinent at that visit.

Inclusion Criteria: Receive a minimum of four mental health treatment sessions from the SOPP that span at least a 1-month interval SOPP treatment plan must indicate intent to deliver ongoing PTSD care for at least 1 year, including visits at least once per month Diagnosis of PTSD resulting from military trauma using DSM-IV criteria Current nicotine use, smoking greater at least 10 cigarettes per day for at least 16 of the past 30 days prior to randomization Demonstrated motivation to quit smoking Exclusion Criteria: Use of smokeless tobacco or smoke pipes or cigars Any psychotic disorder that is not in remission Bipolar disorder that is not in remission Any substance dependence disorder that is not in remission (current substance abuse disorder and substance dependence disorder in remission for more than 1 month are not exclusions) Imminent risk for suicide or violence, as determined during routine assessment by SOPP clinical staff Severe psychiatric symptoms or psychosocial instability likely to prevent participation in the study protocol (i.e., attendance at scheduled sessions, ability to read study materials, and/or ability to comprehend interventions), as determined during routine assessment by SOPP clinical staff Gross impairment from organic mental disorder, as determined during routine assessment by SOPP clinical staff

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McFall M, Saxon AJ, Malte CA, Chow B, Bailey S, Baker DG, Beckham JC, Boardman KD, Carmody TP, Joseph AM, Smith MW, Shih MC, Lu Y, Holodniy M, Lavori PW; CSP 519 Study Team. Integrating tobacco cessation into mental health care for posttraumatic stress disorder: a randomized controlled trial. JAMA. 2010 Dec 8;304(22):2485-93. doi: 10.1001/jama.2010.1769.

Barnett PG, Jeffers A, Smith MW, Chow BK, McFall M, Saxon AJ. Cost-Effectiveness of Integrating Tobacco Cessation Into Post-Traumatic Stress Disorder Treatment. Nicotine Tob Res. 2016 Mar;18(3):267-74. doi: 10.1093/ntr/ntv094. Epub 2015 May 4.

Joseph AM, McFall M, Saxon AJ, Chow BK, Leskela J, Dieperink ME, Carmody TP, Beckham JC. Smoking intensity and severity of specific symptom clusters in posttraumatic stress disorder. J Trauma Stress. 2012 Feb;25(1):10-6. doi: 10.1002/jts.21670. Epub 2012 Feb 10.

Harder LH, Chen S, Baker DG, Chow B, McFall M, Saxon A, Smith MW. The influence of posttraumatic stress disorder numbing and hyperarousal symptom clusters in the prediction of physical health status in veterans with chronic tobacco dependence and posttraumatic stress disorder. J Nerv Ment Dis. 2011 Dec;199(12):940-5. doi: 10.1097/NMD.0b013e3182392bfb.