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Dive into the research topics where Roger Bolus is active.

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Featured researches published by Roger Bolus.


Journal of Nervous and Mental Disease | 2007

Psychometric Properties of the Early Trauma Inventory-Self Report

J. Douglas Bremner; Roger Bolus; Emeran A. Mayer

Childhood trauma is an important public health problem, but there are limitations in our ability to measure childhood abuse. The purpose of this study was to develop a self-report instrument for the assessment of childhood trauma that is valid but simple to administer. A total of 288 subjects with and without trauma and psychiatric disorders were assessed with the Early Trauma Inventory–Self Report (ETI-SR), an instrument for the assessment of physical, emotional, and sexual abuse, as well as general traumas, which measures frequency, onset, emotional impact, and other variables. Validity and consistency of the ETI-SR using different methods of scoring was assessed. The ETI-SR was found to have good validity and internal consistency. No method was found to be superior to the simple method of counting the number of items endorsed as having ever occurred in terms of validity. Some items were found to be redundant or not necessary for the accurate measurement of trauma severity within specific domains. Subsequent analyses with a shortened checklist of items showed acceptable validity and internal consistency. These findings suggest that the ETI-SR is a valid measure of early trauma, and suggest future directions for a shortened version of the ETI-SR that could be more easily incorporated into clinical research studies and practice settings.


Alimentary Pharmacology & Therapeutics | 2004

The Visceral Sensitivity Index: development and validation of a gastrointestinal symptom-specific anxiety scale.

Jennifer S. Labus; Roger Bolus; Lin Chang; Ingela Wiklund; Jørgen Næsdal; Emeran A. Mayer; Bruce D. Naliboff

Background : Anxiety related to gastrointestinal sensations, symptoms or the contexts in which these may occur is thought to play a significant role in the pathophysiology as well as in the health outcomes of patients with irritable bowel syndrome.


Psychosomatic Medicine | 2007

The central role of gastrointestinal-specific anxiety in irritable bowel syndrome: further validation of the visceral sensitivity index.

Jennifer S. Labus; Emeran A. Mayer; Lin Chang; Roger Bolus; Bruce D. Naliboff

Objectives: The Visceral Sensitivity Index (VSI) was developed as the first instrument to assess gastrointestinal-specific anxiety, the cognitive, affective, and behavioral response to fear of gastrointestinal sensations, symptoms, and the context in which these visceral sensations and symptoms occur. The purpose of the current study was to a) replicate the previously reported psychometric properties of the VSI, b) assess the known-groups and concurrent validity of the instrument, and c) test conceptual hypotheses regarding gastrointestinal-specific anxiety in comparison to other general measures of psychological distress as a crucial mechanism (mediator/moderator) underlying irritable bowel syndrome diagnosis and its symptoms. Methods: Two undergraduate student samples (n > 500) were administered the VSI along with measures assessing presence of lower gastrointestinal symptoms, nongastrointestinal pain, health-service utilization, anxiety, depression, vitality, neuroticism, and anxiety sensitivity. Path analyses tested the hypothesis that gastrointestinal-specific anxiety mediates the relationship between affective variables and irritable bowel syndrome diagnosis and symptoms. A ‘known-groups’ validity approach elucidated the relevance of gastrointestinal-specific anxiety across a spectrum of irritable bowel syndrome patients. Results: Good concurrent, divergent and discriminant validity was demonstrated. Logistic regression revealed that gastrointestinal-specific anxiety is the key explanatory variable of irritable bowel syndrome diagnostic status. Path analysis demonstrated that gastrointestinal-specific anxiety mediates the relationship between general psychological distress measures and gastrointestinal symptom severity. The VSI was related to gastrointestinal, but not nongastrointestinal, symptom severity. Conclusions: Overall, the VSI demonstrated excellent psychometric properties providing further support for its use in mechanistic studies of the role of anxiety in irritable bowel syndrome presentation. ANX = anxiety; ASI = Anxiety Sensitivity Index; BSQ-SF = Bowel Symptom Questionnaire-Short Form; DEP = depression; EPQN = Eysenck Personality Questionnaire-Short Form; GI = gastrointestinal; HAD = Hospital Anxiety and Depression Scale; IBS = irritable bowel syndrome; VIT = Medical Outcomes Study-SF-36 energy/fatigue subscale; VSI = Visceral Sensitivity Index.


Clinical Gastroenterology and Hepatology | 2013

Long-term Risk of Acute Diverticulitis Among Patients With Incidental Diverticulosis Found During Colonoscopy

Kamyar Shahedi; Garth Fuller; Roger Bolus; Erica R. Cohen; Michelle Vu; Rena Shah; Nikhil Agarwal; Marc Kaneshiro; Mary A. Atia; Victoria Sheen; Nicole Kurzbard; Martijn G. van Oijen; Linnette Yen; Paul Hodgkins; M. Haim Erder; Brennan M. Spiegel

BACKGROUND & AIMS Colonic diverticulosis is the most common finding during routine colonoscopy, and patients often question the significance of these lesions. Guidelines state that these patients have a 10% to 25% lifetime risk of developing acute diverticulitis. However, this value was determined based on limited data, collected before population-based colonoscopy, so the true number of cases of diverticulosis was not known. We measured the long-term risk of acute diverticulitis among patients with confirmed diverticulosis discovered incidentally on colonoscopy. METHODS We performed a retrospective study using administrative and clinical data from the Veterans Affairs Greater Los Angeles Healthcare System, collecting data on patients who underwent colonoscopies from January 1996 through January 2011. We identified patients diagnosed with diverticulosis, determined incidence rates per 1000 patient-years, and analyzed a subgroup of patients with rigorously defined events confirmed by imaging or surgery. We used a Cox proportional hazards model to identify factors associated with the development of diverticulitis. RESULTS We identified 2222 patients with baseline diverticulosis. Over an 11-year follow-up period, 95 patients developed diverticulitis (4.3%; 6 per 1000 patient-years); of these, 23 met the rigorous definition of diverticulitis (1%; 1.5 per 1000 patient-years). The median time-to-event was 7.1 years. Each additional decade of age at time of diagnosis reduced the risk for diverticulitis by 24% (hazard ratio, 0.76; 95% confidence interval, 0.6-0.9). CONCLUSIONS Based on a study of the Veterans Affairs Greater Los Angeles Healthcare System, only about 4% of patients with diverticulosis develop acute diverticulitis, contradicting the common belief that diverticulosis has a high rate of progression. We also found that younger patients have a higher risk of diverticulitis, with risk increasing per year of life. These results can help inform patients with diverticulosis about their risk of developing acute diverticulitis.


The American Journal of Gastroenterology | 2005

Characterization of the alternating bowel habit subtype in patients with irritable bowel syndrome.

Kirsten Tillisch; Jennifer S. Labus; Bruce D. Naliboff; Roger Bolus; Michael Shetzline; Emeran A. Mayer; Lin Chang

BACKGROUND:Due to a wide range of symptom patterns, patients with irritable bowel syndrome (IBS) are often subgrouped by bowel habit. However, the IBS subgroup with alternating bowel habits (IBS-A) has been poorly characterized.OBJECTIVES:(i) To determine a set of bowel habit symptom criteria, which most specifically identifies IBS patients with an alternating bowel habit, (ii) to describe IBS-A bowel symptom patterns, and (iii) to compare clinical characteristics among IBS-A, constipation-predominant (IBS-C), and diarrhea-predominant IBS (IBS-D).METHODS:One thousand one hundred and two Rome I positive IBS patients were analyzed. Three sets of potential criteria for IBS-A were developed and compared by multirater Kappa test. Gastrointestinal, psychological, extraintestinal symptoms, and health-related quality of life were compared in IBS-A, IBS-C, and IBS-D using χ2 test and analysis of variance (ANOVA).RESULTS:Stool consistency was determined to be the most specific criteria for alternating bowel habits. IBS-A patients reported rapid fluctuations in bowel habits with short symptom flares and remissions. There was a greater prevalence of psychological and extraintestinal symptoms in the IBS-A subgroup compared to IBS-C and IBS-D. No differences were seen between bowel habit subtypes in health-related quality of life.CONCLUSIONS:IBS-A patients have rapidly fluctuating symptoms and increased psychological comorbidity, which should be taken into account for clinical practice and clinical trials.


Psychosomatic Medicine | 2004

The effect of life stress on symptoms of heartburn.

Bruce D. Naliboff; Minou Mayer; Ronnie Fass; Leah FitzGerald; Lin Chang; Roger Bolus; Emeran A. Mayer

Objective: Psychosocial stressors have been associated with exacerbations of symptoms in functional and inflammatory disorders of the gastrointestinal tract. The present longitudinal study tests the general hypothesis that life stressors can exacerbate symptoms in patients with chronic heartburn. Methods: Sixty subjects with current heartburn symptoms were recruited by community advertisement and assessed for presence of stressful life events retrospectively over the preceding 6 months and prospectively for 4 months. Symptom severity by daily diary, quality of life, and psychological symptoms of anxiety, depression, and vital exhaustion were also measured. Results: The presence of a severe, sustained life stress during the previous 6 months significantly predicted increased heartburn symptoms during the following 4 months. In addition, symptoms showed a strong, independent correlation with vital exhaustion. Affective and subjective stress ratings were not strongly related to heartburn severity; however, anxiety showed the strongest relationship to impaired quality of life and depression to heartburn medication use. Conclusions: As with other chronic conditions such as irritable bowel syndrome (IBS), heartburn severity appears to be most responsive to major life events and not an accumulation of more minor stressors or fluctuations in mood. In addition, vital exhaustion, which may in part result from sustained stress, may represent the psychophysiological symptom complex most closely associated with heartburn exacerbation. Potential mechanisms for these results include increased level and frequency of esophageal acid exposure, inhibition of gastric emptying of acid, or stress-induced hypersensitivity.


The American Journal of Gastroenterology | 2011

Development and validation of a novel patient educational booklet to enhance colonoscopy preparation.

Brennan M. Spiegel; Jennifer Talley; Paul G. Shekelle; Nikhil Agarwal; Bradley J. Snyder; Roger Bolus; Nicole Kurzbard; Michael Chan; Andrew Ho; Marc Kaneshiro; Kristina Cordasco; Hartley Cohen

OBJECTIVES:The success of colonoscopy depends on high-quality bowel preparation by patients; yet inadequate preparation is common. We developed and tested an educational booklet to improve bowel preparation quality.METHODS:We conducted patient cognitive interviews to identify knowledge and belief barriers to colonoscopy preparation. We used these interviews to create an educational booklet to enhance preparatory behaviors. We then prospectively randomized patients scheduled for outpatient colonoscopy at a VA Medical Center to receive usual instructions vs. the booklet before colonoscopy. Patients in both groups received standard pharmacy instructions for single-dose bowel preparation; the protocol did not specify which purgatives to prescribe. The primary outcome was preparation quality based on blinded ratings using the validated Ottawa score. We performed bivariate analyses to compare mean scores between groups using a t-test, and logistic regression to measure the booklet effect on preparation quality, adjusting for potential confounders.RESULTS:A total of 436 patients were randomized between arms. In an intention-to-treat analysis of the primary outcome, mean Ottawa scores were superior in patients allocated to booklet vs. controls (P=0.03). An intention-to-treat analysis of the secondary outcome revealed a “good” preparation in 68 vs. 46% of booklet and control patients, respectively (P=0.054). In a per-protocol analysis limited to patients who actually received the booklet, preparation was good in 76 vs. 46% patients, respectively (P<0.00001). Regression analysis revealed that booklet receipt increased the odds of good preparation by 3.7 times (95% confidence interval=2.3–5.8).CONCLUSIONS:Provision of a novel educational booklet considerably improves preparation quality in patients receiving single-dose purgatives. The effect of the booklet on split-dose purgatives remains untested and will be evaluated in future research.


Clinical Gastroenterology and Hepatology | 2009

Health-Related Quality of Life Predicts Mortality in Patients With Advanced Chronic Liver Disease

Fasiha Kanwal; Ian M. Gralnek; Ron D. Hays; Angelique Zeringue; Francisco Durazo; Steven B. Han; Sammy Saab; Roger Bolus; Brennan M. Spiegel

BACKGROUND & AIMS It is well-established that cirrhosis negatively impacts health-related quality of life (HRQOL). However, it is less clear how to use this information in everyday clinical practice. If HRQOL predicted survival in cirrhosis, then measuring HRQOL would have important clinical implications. We sought to measure the association between HRQOL and survival in patients with cirrhosis and investigated whether the relationship between HRQOL and survival is independent of Model for End-Stage Liver Disease (MELD). METHODS We measured HRQOL in 156 patients with cirrhosis awaiting liver transplantation by using the Short Form Liver Disease Quality of Life instrument. We followed patients prospectively and used Cox proportional hazard models to measure the independent effect of baseline HRQOL on survival, adjusting for MELD and other covariates. RESULTS During a mean 9-month follow-up, 26 (17%) patients died, and 30 (20%) received liver transplants. In unadjusted analysis, higher baseline HRQOL predicted lower mortality (hazard ratio, 0.96; 95% confidence interval, 0.94-0.99). Specifically, for each 1-point increase in HRQOL, there was a 4% decrease in mortality. These results did not change after adjusting for MELD scores, patient demographics, or psychosocial characteristics; the MELD score accounted for 1% of the variation in HRQOL scores (P = .18). Survival was most strongly predicted by activities of daily living, health distress, sleep disturbance, and perceived disease stigma. CONCLUSIONS Higher HRQOL predicts lower mortality in patients with cirrhosis. This relationship is independent of MELD; MELD does not capture liver-specific HRQOL. Beyond its use as a secondary outcome in clinical trials, HRQOL could be used to predict survival of patients with advanced liver disease.


Alimentary Pharmacology & Therapeutics | 2009

Measuring irritable bowel syndrome patient‐reported outcomes with an abdominal pain numeric rating scale

Brennan M. Spiegel; Roger Bolus; L. A. Harris; Susan L. Lucak; Bruce D. Naliboff; Eric Esrailian; William D. Chey; Anthony Lembo; H. Karsan; Kirsten Tillisch; Jennifer Talley; Emeran A. Mayer; Lin Chang

Background  Controversy exists on how to measure patient‐reported outcomes in irritable bowel syndrome (IBS) clinical trials effectively. Pain numeric rating scales (NRS) are widely used in the non‐IBS pain literature. The Food and Drug Administration has proposed using the NRS in IBS.


Clinical Gastroenterology and Hepatology | 2013

Increased Risk for Irritable Bowel Syndrome After Acute Diverticulitis

Erica R. Cohen; Garth Fuller; Roger Bolus; Rusha Modi; Michelle Vu; Kamyar Shahedi; Rena Shah; Mary A. Atia; Nicole Kurzbard; Victoria Sheen; Nikhil Agarwal; Marc Kaneshiro; Linnette Yen; Paul Hodgkins; M. Haim Erder; Brennan M. Spiegel

BACKGROUND & AIMS Individuals with diverticulosis frequently also have irritable bowel syndrome (IBS), but there are no longitudinal data to associate acute diverticulitis with subsequent IBS, functional bowel disorders, or related emotional distress. In patients with postinfectious IBS, gastrointestinal disorders cause long-term symptoms, so we investigated whether diverticulitis might lead to IBS. We compared the incidence of IBS and functional bowel and related affective disorders among patients with diverticulitis. METHODS We performed a retrospective study of patients followed up for an average of 6.3 years at a Veterans Administration medical center. Patients with diverticulitis were identified based on International Classification of Diseases, 9th revision codes, selected for the analysis based on chart review (cases, n = 1102), and matched with patients without diverticulosis (controls, n = 1102). We excluded patients with prior IBS, functional bowel, or mood disorders. We then identified patients who were diagnosed with IBS or functional bowel disorders after the diverticulitis attack, and controls who developed these disorders during the study period. We also collected information on mood disorders, analyzed survival times, and calculated adjusted hazard ratios. RESULTS Cases were 4.7-fold more likely to be diagnosed later with IBS (95% confidence interval [CI], 1.6-14.0; P = .006), 2.4-fold more likely to be diagnosed later with a functional bowel disorder (95% CI, 1.6-3.6; P < .001), and 2.2-fold more likely to develop a mood disorder (CI, 1.4-3.5; P < .001) than controls. CONCLUSIONS Patients with diverticulitis could be at risk for later development of IBS and functional bowel disorders. We propose calling this disorder postdiverticulitis IBS. Diverticulitis appears to predispose patients to long-term gastrointestinal and emotional symptoms after resolution of inflammation; in this way, postdiverticulitis IBS is similar to postinfectious IBS.

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Brennan M. Spiegel

Cedars-Sinai Medical Center

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Lin Chang

University of California

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Nikhil Agarwal

University of California

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Garth Fuller

Cedars-Sinai Medical Center

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Cynthia B. Whitman

Cedars-Sinai Medical Center

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