Predicting response to and relapse after treatment of trichotillomania with the Comprehensive Behavioral model (ComB).

Prior studies of behavior therapy for trichotillomania (TTM) have shown that response is variable, and relapse after treatment discontinuation is common. Little information is available concerning prognostic factors capable of predicting individual differences in response or maintenance of improvement. The present study is a secondary analysis of a randomized controlled trial (N = 36) of the Comprehensive Behavioral (ComB) model of treatment for TTM (Carlson et al., 2021). We investigated age, disorder history, pre-treatment symptom severity, longest prior period of abstinence from pulling, and Emotion and Intention hair pulling styles as predictors of initial response. We studied age, disorder history, pre-treatment symptom severity, longest prior period of abstinence from pulling, and post-treatment symptom severity or hair-pulling abstinence as predictors of relapse following treatment. Older age significantly predicted lower TTM severity following treatment. Lower pre-treatment severity significantly predicted lower severity of TTM at the 3-month follow-up.

Rationale, formative research, and protocol for Calma, Conversa, y Cría: A pilot mindful parenting intervention with Latina women.

Background: Latina mothers' stress is associated with their children's health behaviors and risk for obesity; however, existing pediatric health promotion programs have not focused on maternal stress reduction. Methods: Herein we describe a study design that will examine the acceptability and feasibility of Calma, Conversa, y Cría (CCC) a 6-week mindful parenting intervention designed to reduce stress. We present the results of qualitative research with Latina mothers and experts in Latinx health and mindfulness who provided culturally-relevant feedback on existing mindful parenting strategies to inform the development of CCC. Fifty Latina mothers of children ages 3-11 years will be randomly assigned to CCC or an enhanced usual care health education intervention. Acceptability will be assessed through participant satisfaction surveys and exit interviews. Feasibility will be determined through detailed tracking of recruitment, retention, and attendance rates. A signal regarding any group differences in maternal stress, health-related parenting practices, child diet, child physical activity, and child quality of life will be explored. Discussion: The development of interventions that can reduce maternal stress and risk for obesity in Latinx children is critical to significantly reduce negative health impacts in this underserved population. Our approach includes the identification of effective cultural adaptations that should improve the feasibility and acceptability of mindful parenting strategies in Latinx families, ideally reducing maternal stress and improving parenting behaviors related to child health. If successful, CCC will be examined in a larger efficacy trial involving the measurement of objective biomarkers of children's chronic disease risk.

Comprehensive Behavioral (ComB) Treatment of Trichotillomania: A Randomized Clinical Trial.

OBJECTIVE: This study is the first controlled trial of comprehensive behavioral (ComB) treatment of trichotillomania (TTM). ComB provides individualized treatment based on factors triggering and maintaining hair pulling. METHOD: Participants (N = 36) were adults (M = 34.08 years old, SD = 12.26) meeting DSM5 criteria for TTM. A majority were female (80%) and Caucasian (75%), whereas 17% were African American and 19% Hispanic/Latinx. In a parallel-group design, participants were randomly assigned to (a) Immediate ComB (12 sessions) or (b) Minimal Attention Control (MAC), followed by delayed ComB after week 12. Follow-up continued through week 38. Primary outcomes were self-report (Massachusetts General Hospital Hair pulling Scale; MGH-HPS) and interviewer-rated (NIMH-Trichotillomania Impact Scale and Trichotillomania Severity Scale; TIS/TSS) TTM symptom severity, as well as diagnosis (Trichotillomania Diagnostic Interview). RESULTS: Immediate efficacy of ComB (vs. MAC) was statistically significant (p = .03) for self-reported symptoms, with an effect size d = -.78, but not significant for interviewer-rated symptoms or diagnostic status. Immediate ComB was significantly more likely than MAC (27% vs. 0%) to lead to complete abstinence from hair pulling at week 12. Follow-ups showed good maintenance of effects. CONCLUSIONS: Efficacy of ComB was established for self-reported symptoms. Future research is needed to establish whether the lack of more widespread effects stems from limitations of the model or to a need for more extensive therapist training, as secondary analyses suggested stronger results among therapists with more TTM experience.

Validation of the Revised Strain Index for Predicting Risk of Incident Carpal Tunnel Syndrome in a Prospective Cohort.

The Revised Strain Index (RSI), a model that quantifies physical exposure from individual hand/wrist exertions, tasks, and multi-task jobs, was used to quantify exposure for 1372 incident-eligible manufacturing, service and healthcare workers. Workers were followed for an average of 2.5 years (maximum 6 years) and had an average carpal tunnel syndrome (CTS) incidence rate of 4.6 per 100 person-years. Exceeding the a-priori RSI limit of 10.0 showed increased risk of CTS (Hazard Ratio (HR) = 1.45, 95% CI: 1.11-1.91, p = 0.01). There also was a dose-response relationship using proposed low (RSI ≤ 8.5, HR = 1.00), medium (HR = 1.42 (95% CI: 0.96-2.09, p = 0.08)), and high limits (RSI > 15, HR = 1.79 (95% CI: 1.19-2.69, p = 0.01), respectively. RSI as a continuous variable showed CTS risk increased steadily by between 1.9% and 3.3% per unit increase in RSI (p ≤ 0.03). These results suggest that the RSI is a useful tool for surveillance as well as for job intervention/design and continuous improvement processes.Practitioner Summary The Revised Strain Index (RSI) quantifies physical exposure from individual hand/wrist exertions, tasks, and multi-task jobs. Increased cumulative RSI scores (i.e. daily exposure score) are associated with increased risk of carpal tunnel syndrome (CTS). The RSI is potentially useful as a risk surveillance and intervention design tool.

Bayesian Wavelet-packet Historical Functional Linear Models.

Historical Functional Linear Models (HFLM) quantify associations between a functional predictor and functional outcome where the predictor is an exposure variable that occurs before, or at least concurrently with, the outcome. Prior work on the HFLM has largely focused on estimation of a surface that represents a time-varying association between the functional outcome and the functional exposure. This existing work has employed frequentist and spline-based estimation methods, with little attention paid to formal inference or adjustment for multiple testing and no approaches that implement wavelet-bases. In this work, we propose a new functional regression model that estimates the time-varying, lagged association between a functional outcome and a functional exposure. Building off of recently developed function-on-function regression methods, the model employs a novel use the wavelet-packet decomposition of the exposure and outcome functions that allows us to strictly enforce the temporal ordering of exposure and outcome, which is not possible with existing wavelet-based functional models. Using a fully Bayesian approach, we conduct formal inference on the time-varying lagged association, while adjusting for multiple testing. We investigate the operating characteristics of our wavelet-packet HFLM and compare them to those of two existing estimation procedures in simulation. We also assess several inference techniques and use the model to analyze data on the impact of lagged exposure to particulate matter finer than 2.5µg, or PM2.5, on heart rate variability in a cohort of journeyman boilermakers during the morning of a typical day's shift.

Lower self-efficacy and greater depressive symptoms predict greater failure to recover from a single lapse cigarette.

OBJECTIVE: Smoking reexposure after a quit attempt (i.e., lapse) increases relapse risk, but lapse recovery is possible. Using a 6-day analogue model of smoking cessation and lapse, this study tested the effect of a single lapse cigarette on the risk of subsequent smoking. Abstinence self-efficacy (ASE) and depressive symptoms (using the Center for Epidemiological Studies Depression Scale, CES-D) were also examined as hypothesized moderators of lapse recovery. METHOD: After receiving cessation counseling and achieving 2 days of incentivized abstinence, 54 daily smokers (mean age: 41 years, 61% African American, 63% male) were randomly assigned to smoke 1 cigarette or to a no-lapse control condition. Participants were then offered monetary incentives to abstain for 3 more days and smoking was monitored. RESULTS: Compared to the control condition, participants who experienced a lapse had a 2.5 times greater risk of smoking in the first 24 hours Furthermore, a lapse resulted in much greater risk of subsequent smoking compared to the control condition among individuals with lower postquit ASE scores (p = .044) and greater CES-D scores (p = .040). CONCLUSIONS: These findings provide preliminary evidence that a single lapse cigarette after quitting plays a causal role in subsequent smoking and suggest that individuals with lower postquit ASE and greater depressive symptoms are less likely to recover from a lapse. Future research should investigate factors associated with lapse recovery and failure so that effective lapse-responsive strategies can be developed. Laboratory models provide an efficient and controlled method to examine such processes. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Psychosocial Factors and Low Back Pain Outcomes in a Pooled Analysis of Low Back Pain Studies.

OBJECTIVE: Assessment of possible relationships between work-related psychosocial measures and self-reported low back pain (LBP) outcomes in a large pooled dataset of 1929 participants from 82 facilities in the United States. METHODS: Pooled data from three prospective cohort studies were used to calculate odds ratios (OR) and 95% confidence intervals (95% CI) for relationships between psychosocial factors and the LBP outcomes. Personal and occupational confounders were controlled for in adjusted Logistic regression models. RESULTS: Supervisor support and job satisfaction were significantly (P < 0.05) related to all three LBP outcomes. Other psychosocial factors were significantly (P < 0.05) associated with at least one of the LBP outcomes. Adjusted ORs ranged from approximately 1.50 to 3.50 for most associations. CONCLUSIONS: There is a significant relationship between work-related psychosocial measures and LBP outcomes.

Ovarian cyclicity and prolactin status of African elephants (Loxodonta africana) in North American zoos may be influenced by life experience and individual temperament.

Hyperprolactinemia is an endocrine disorder associated with infertility in many species, including elephants. In a recent survey of zoos accredited by the Association of Zoos and Aquariums (AZA), over half of African elephant females (N = 101) were not cycling normally, 30% of which exhibited hyperprolactinemia. We examined whether life experience and temperament predict ovarian cyclicity and circulating prolactin status in individual African elephant females. We hypothesized that, similar to humans, acyclicity and hyperprolactinemia in elephants will be associated with an apprehensive or fearful, anxious temperament, and an increased number of potentially challenging life events (transfers, deaths and births). Ninety-five adult African elephant females housed at 37 AZA institutions were included in this study. Blood samples were collected twice a month for 1 year to determine ovarian cycle (cycling, n = 44; irregular, n = 13; non-cycling, n = 38) and prolactin (normal, n = 44; low; n = 23; high; n = 28) status. Keeper ratings on a 6-point scale were obtained on 32 temperament traits in 85 of these elephants. We determined that giving birth and being exposed to herd mates entering the facility were positively associated with normal ovarian cycle and prolactin profiles. By contrast, age, serum cortisol, and an increased number of herd mates leaving a facility were negatively associated with both. Contrary to our hypothesis, hyperprolactinemia was associated with a popular and caring temperament rating, whereas consistently low prolactin was associated with a fearful, apprehensive temperament. These findings indicate that pituitary-ovarian function may be impacted by life history (cyclicity) and temperament (prolactin), which should be taken into consideration when making management decisions.

Looming Vulnerability and Smoking Cessation Attempts.

INTRODUCTION: The looming vulnerability model holds that people become anxious when they perceive threats as growing larger and accelerating toward them in space and time. Preliminary research suggested that a guided imagery induction designed to activate a sense that health consequences of smoking are a looming threat led more smokers to attempt to quit. This study tested the effect on quit attempts in a larger sample and examined age, sex, and sensation seeking as moderators. AIMS AND METHODS: Adult smokers (≥10 cigarettes/day) screened for risk of anxiety or mood disorders (N = 278, 52% male; 77% African American) were randomly assigned to receive (1) looming vulnerability or (2) neutral guided imagery exercises. At a 4-week follow-up, they reported quit attempts, smoking rate, self-efficacy, outcome expectancies, and contemplation status. RESULTS: Those in the looming condition (17%) were no more likely than those in the control condition (20%) to make a quit attempt. There were no significant group differences in expectancies, contemplation, or follow-up smoking rate, and no significant moderators. CONCLUSIONS: The looming induction was the same one used in earlier work in which it had stronger effects. Those who respond to it with increased urgency about quitting smoking might be offset by others who are more reactant and deny the message. Inconsistencies across studies may reflect differences in inclusion criteria, such that the present sample was on average heavier smokers with longer smoking history and more severe nicotine dependence, yet higher self-efficacy. IMPLICATIONS: An induction designed to activate a sense that the health consequences of smoking constitute a looming vulnerability failed to increase quit attempts or reduce smoking rate among adult daily smokers. Inconsistencies across studies might reflect varying sample characteristics resulting from changes in screening criteria.

Examining outcome expectancies for smoking vs. abstinence among adult daily smokers.

In a motivational interviewing (MI) framework of decision-making, we consider potential outcomes for both a primary choice and an alternative choice (DiClemente & Velazquez, 2002). Thus, we would expect that motivation to quit smoking is related to expectancies for quitting smoking and expectancies for continuing to smoke. While smoking expectancies have been frequently studied, less attention has been paid to abstinence expectancies. The present study sought to clarify the predictive utility of smoking and abstinence expectancies together for smoking motivation and behavior, versus measuring smoking expectancies alone. Expectancies were measured at baseline; outcomes were measured at baseline and one-month follow-up. Smoking expectancies were assessed via the Smoking Consequences Questionnaire-Adult (Copeland, Brandon, & Quinn, 1995), and abstinence expectancies were assessed via the Perceived Risks and Benefits of Quitting scale (McKee, O'Malley, Salovey, Krishnan-Sarin, & Mazure, 2005). Outcomes included motivation to quit (Contemplation Ladder, Biener & Abrams, 1991; Stage of Change, DiClemente et al., 1991), and average daily smoking rate. Data was analyzed for 183 smokers at baseline and 166 at follow-up. Baseline smoking expectancies and abstinence expectancies were each uniquely associated with concurrent motivation to quit, but not concurrent smoking rate. Abstinence expectancies uniquely predicted changes in smoking rate over time. Smoking and abstinence outcome expectancies may relate differently to smoking behavior, motivation to quit, and changes in these constructs over time.

Differential behavioral effects of ethanol pre-exposure in male and female zebrafish (Danio rerio).

Alcohol exposure in adolescence is a contributing factor toward reward-seeking behavior in adulthood. This reward-seeking behavior is assessed in animal models using the conditioned place preference (CPP) paradigm. In this study, ethanol-induced change in time spent by zebrafish on the initially non-preferred tank side was studied by conditioning adult zebrafish to ethanol dissolved in water (0.00% 1.00%; 1.25%; 1.50%; 1.60%; 1.75% vol/vol) paired with an initially non-preferred environment. Following a single conditioning cycle, fish swam unrestricted in the CPP chamber to assess changes in preference. Daily 20-min pre-exposure to ethanol for 1 week during the juvenile stage starting at either 20days post fertilization (dpf) or 40 dpf altered percent time spent on the ethanol-paired side in adulthood in a dose-dependent and sex-dependent manner. The results suggest that male and female zebrafish are an effective model in which to investigate behavioral correlates of ethanol-induced changes in neural circuits implicated in reward and anxiety.

Estimating and Interpreting Effects from Nonlinear Exposure-Response Curves in Occupational Cohorts Using Truncated Power Basis Expansions and Penalized Splines.

Truncated power basis expansions and penalized spline methods are demonstrated for estimating nonlinear exposure-response relationships in the Cox proportional hazards model. R code is provided for fitting models to get point and interval estimates. The method is illustrated using a simulated data set under a known exposure-response relationship and in a data application examining risk of carpal tunnel syndrome in an occupational cohort.

Evaluation of Demographics and Social Life Events of Asian (Elephas maximus) and African Elephants (Loxodonta africana) in North American Zoos.

This study quantified social life events hypothesized to affect the welfare of zoo African and Asian elephants, focusing on animals that were part of a large multi-disciplinary, multi-institutional elephant welfare study in North America. Age was calculated based on recorded birth dates and an age-based account of life event data for each elephant was compiled. These event histories included facility transfers, births and deaths of offspring, and births and deaths of non-offspring herd mates. Each event was evaluated as a total number of events per elephant, lifetime rate of event exposure, and age at first event exposure. These were then compared across three categories: species (African vs. Asian); sex (male vs. female); and origin (imported vs. captive-born). Mean age distributions differed (p<0.05) between the categories: African elephants were 6 years younger than Asian elephants, males were 12 years younger than females, and captive-born elephants were 20 years younger than imported elephants. Overall, the number of transfers ranged from 0 to 10, with a 33% higher age-adjusted transfer rate for imported African than imported Asian elephants, and 37% lower rate for imported females than males (p<0.05). Other differences (p<0.05) included a 96% higher rate of offspring births for captive-born females than those imported from range countries, a 159% higher rate of birthing event exposures for captive-born males than for their imported counterparts, and Asian elephant females being 4 years younger than African females when they produced their first calf. In summarizing demographic and social life events of elephants in North American zoos, we found both qualitative and quantitative differences in the early lives of imported versus captive-born elephants that could have long-term welfare implications.

Race/Ethnicity and Treatment Outcome in a Randomized Controlled Trial for Trichotillomania (Hair-Pulling Disorder).

OBJECTIVE: Treatment outcome was compared among non-Hispanic White and racial/ethnic minority participants with trichotillomania (TTM), or hair-pulling disorder. METHOD: Symptom severity, quality of life, and TTM-related disability were compared in a behavior therapy trial with a stepped care approach: web-based self-help and then individual behavior therapy. The sample comprised 72% (n = 38) non-Hispanic White participants and 28% (n = 15) minority participants. RESULTS: The ethnic groups responded differently to treatment, with fewer minority participants showing improvement during web-based self-help. Response rates were equivalent between ethnic groups during the in-person behavior therapy. These results should be interpreted with caution because of the small sample size of minorities in the study and consequent inability to analyze results for each racial/ethnic group individually. CONCLUSIONS: Future studies should focus on the investigation of factors that may enable or hinder racial and ethnic minority participants to benefit from online and/or self-help behavior therapy for TTM.

Predictors of Relapse Following Treatment of Trichotillomania.

OBJECTIVE: This study sought to identify predictors of relapse in a behavior therapy trial for trichotillomania (TTM), or hair-pulling disorder. Relapse is common after treatment for TTM, and only a few studies have examined what might predict relapse. METHOD: Data was examined from a TTM treatment study with a stepped-care approach (step 1. web-based self-help; step 2. individual behavior therapy) (N = 60). Implications of significant predictive relations were illustrated by constructing Probability of Treatment Benefit (PTB) charts (Lindhiem, Kolko, & Cheng, 2012), which quantify the probability of maintaining gains according to predictors of maintenance. RESULTS: Abstinence at the conclusion of treatment and lower TTM severity during initial response significantly predicted maintenance. Abstinence periods prior to treatment, residual urges after achieving abstinence, pre-treatment TTM severity, intrinsic motivation, and treatment compliance did not predict maintenance. CONCLUSIONS: Post-treatment abstinence and lower TTM severity during initial response predicted maintenance. Replications of this research are needed to determine the usefulness of these possible predictors in identifying relapse-prone patients, with the aim of improving clinical decision-making and developing strategies to help these patients better maintain gains. This is the first TTM study to use PTB charts, which can help clarify the meaning of prognostic analyses.

Exposure-response relationships for the ACGIH threshold limit value for hand-activity level: results from a pooled data study of carpal tunnel syndrome.

OBJECTIVES: This paper aimed to quantify exposure-response relationships between the American Conference of Governmental Industrial Hygienists' (ACGIH) threshold limit value (TLV) for hand-activity level (HAL) and incidence of carpal tunnel syndrome (CTS). METHODS: Manufacturing and service workers previously studied by six research institutions had their data combined and re-analyzed. CTS cases were defined by symptoms and abnormal nerve conduction. Hazard ratios (HR) were calculated using proportional hazards regression after adjusting for age, gender, body mass index, and CTS predisposing conditions. RESULTS: The longitudinal study comprised 2751 incident-eligible workers, followed prospectively for up to 6.4 years and contributing 6243 person-years of data. Associations were found between CTS and TLV for HAL both as a continuous variable [HR 1.32 per unit, 95% confidence interval (95% CI) 1.11-1.57] and when categorized using the ACGIH action limit (AL) and TLV. Those between the AL and TLV and above the TLV had HR of 1.7 (95% CI 1.2-2.5) and 1.5 (95% CI 1.0-2.1), respectively. As independent variables (in the same adjusted model) the HR for peak force (PF) and HAL were 1.14 per unit (95% CI 1.05-1.25), and 1.04 per unit (95% CI 0.93-1.15), respectively. CONCLUSION: Those with exposures above the AL were at increased risk of CTS, but there was no further increase in risk for workers above the TLV. This suggests that the current AL may not be sufficiently protective of workers. Combinations of PF and HAL are useful for predicting risk of CTS.

Association between lifting and use of medication for low back pain: results from the Backworks Prospective Cohort Study.

OBJECTIVE: To evaluate relationships between lifting and lowering of loads and risk of low back pain resulting in medication use (M-LBP). METHODS: At baseline, worker demographics, psychosocial factors, hobbies, LBP history, and lifting and lowering (quantified using the Revised NIOSH Lifting Equation) were assessed. A cohort of 258 incident-eligible workers was followed up for 4.5 years to determine new M-LBP cases and changes in lifting/lowering requirements. Proportional hazards regression with time-varying covariates was used to model associations. RESULTS: Factors predicting M-LBP included peak lifting index (PLI) and composite lifting index (PCLI), LBP history, anxiety, and housework. In adjusted models, PLI and PCLI showed exposure-response relationships with peak hazard ratios of 3.8 and 4.3, respectively (P ≤ 0.02). CONCLUSIONS: Lifting of loads is associated with increased risk of M-LBP. The PLI and PCLI are useful metrics for estimating the risk of M-LBP from lifting.

Validating indicators of treatment response: application to trichotillomania.

Different studies of the treatment of trichotillomania (TTM) have used varying standards to determine the proportion of patients who obtain clinically meaningful benefits, but there is little information on the similarity of results yielded by these methods or on their comparative validity. Data from a stepped-care (Step 1: Web-based self-help; Step 2: Individual behavior therapy; N = 60) treatment study of TTM were used to evaluate 7 potential standards: complete abstinence, ≥ 25% symptom reduction, recovery of normal functioning, and clinical significance (recovery + statistically reliable change), each of the last 3 being measured by self-report (Massachusetts General Hospital Hairpulling Scale; MGH-HPS) or interview (Psychiatric Institute Trichotillomania Scale). Depending on the metric, response rates ranged from 25 to 68%. All standards were significantly associated with one another, though less strongly for the 25% symptom reduction metrics. Concurrent (with deciding to enter Step 2 treatment) and predictive (with 3-month follow-up treatment satisfaction, TTM-related impairment, quality of life, and diagnosis) validity results were variable but generally strongest for clinical significance as measured via self-report. Routine reporting of the proportion of patients who make clinically significant improvement on the MGH-HPS, supplemented by data on complete abstinence, would bolster the interpretability of TTM treatment outcome findings.

The NIOSH lifting equation and low-back pain, Part 1: Association with low-back pain in the backworks prospective cohort study.

OBJECTIVE: The aim of this study was to evaluate relationships between the revised NIOSH lifting equation (RNLE) and risk of low-back pain (LBP). BACKGROUND: The RNLE is commonly used to quantify job physical stressors to the low back from lifting and/or lowering of loads. There is no prospective study on the relationship between RNLE and LBP that includes accounting for relevant covariates. METHOD: A cohort of 258 incident-eligible workers from 30 diverse facilities was followed for up to 4.5 years. Job physical exposures were individually measured. Worker demographics, medical history, psychosocial factors, hobbies, and current LBP were obtained at baseline. The cohort was followed monthly to ascertain development of LBP and quarterly to determine changes in job physical exposure. The relationship between LBP and peak lifting index (PLI) and peak composite lifting index (PCLI) were tested in multivariate models using proportional hazards regression. RESULTS: Point and lifetime prevalences of LBP at baseline were 7.1% and 75.1%, respectively. During follow-up, there were 123 incident LBP cases. Factors predicting development of LBP included job physical exposure (PLI and PCLI), history of LBP, psychosocial factors, and housework. In adjusted models, risk (hazard ratio [HR]) increased per-unit increase in PLI and PCLI (p = .05 and .02; maximum HR = 4.3 and 4.2, respectively). PLI suggested a continuous increase in risk with an increase in PLI, whereas the PCLI showed elevated, but somewhat reduced, risk at higher exposures. CONCLUSION: Job physical stressors are associated with increased risk of LBP. Data suggest that the PLI and PCLI are useful metrics for estimating exposure to job physical stressors.

The NIOSH lifting equation and low-back pain, Part 2: Association with seeking care in the backworks prospective cohort study.

OBJECTIVE: The aim of this study was to investigate the relationship between the revised NIOSH lifting equation (RNLE) and risk of seeking care for low-back pain (SC-LBP). BACKGROUND: The RNLE is commonly used to quantify low-back physical stressors from lifting/lowering of loads in workplaces. There is no prospective study on relationship between RNLE and SC-LBP. METHOD: A cohort of 258 incident-eligible workers from 30 diverse facilities was followed for up to 4.5 years. Job physical exposures were individually measured. Worker demographics, medical history, psychosocial factors, hobbies, and current low-back pain were obtained at baseline. The cohort was followed monthly to ascertain SC-LBP and quarterly to determine changes in physical exposure. Associations between SC-LBP and both the peak lifting index (PLI) and peak composite lifting index (PCLI) were tested in multivariate models using proportional hazards regression. RESULTS: SC-LBP lifetime prevalence at baseline was 31.9%, and there were 24 incident cases during follow-up. Factors predicting SC-LBP included job physical exposure (PLI and PCLI), history of low-back pain, age, female gender, and lower body mass index. In adjusted models, risk (hazard ratio [HR]) increased per unit increase in PLI and PCLI (p = .03 and .02, and maximum HR = 23.0 and 21.9, respectively). Whereas PCLI suggested a continuous increase in risk with an increase in PCLI, the PLI showed elevated, though somewhat reduced, risk at higher exposures (HR = 14.9 at PLI = 6). CONCLUSION: Job physical stressors are associated with increased risk of SC-LBP. Data suggest that both the PLI and PCLI are useful metrics for estimating exposure to job physical stressors.