Ajitha Mannalithara
Stanford University
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Featured researches published by Ajitha Mannalithara.
Gastrointestinal Endoscopy | 2009
Gaurav Arora; Ajitha Mannalithara; Gurkirpal Singh; Lauren B. Gerson; George Triadafilopoulos
BACKGROUND Previous studies that reported the incidence of perforation from a colonoscopy are limited by small sample sizes, restricted age groups, or single-center data. OBJECTIVE To determine the incidence and risk factors of colonic perforation from a colonoscopy in a large population cohort. DESIGN Retrospective, population-based, cohort study, followed by a nested case-control study. SETTING California Medicaid program claims database. PATIENTS A total of 277,434 patients (aged 18 years and older) who underwent a colonoscopy during 1995 to 2005, age, sex, and time matched to 4 unique general-population controls. MAIN OUTCOME MEASUREMENTS Perforation incidence in the 7 days after colonoscopy (or matched index date for controls) with odds ratio (OR); multivariate logistic regression to calculate adjusted ORs for subsequent analysis of risk factors. RESULTS A total of 228 perforations were diagnosed after 277,434 colonoscopies, which corresponded to a cumulative 7-day incidence of 0.082%. The OR of getting a perforation from a colonoscopy compared with matched controls (n = 1,072,723) who did not undergo a colonoscopy was 27.6 (95% CI, 19.04-39.92), P < .001. On multivariate analysis, when comparing the group that had a perforation after a colonoscopy (n = 216) with those who did not (n = 269,496), increasing age, significant comorbidity, obstruction as an indication for the colonoscopy, and performance of invasive interventions during colonoscopy were significant positive predictors. Performance of biopsy or polypectomy did not affect the perforation risk. The rate of perforation did not change significantly over time. LIMITATIONS Validity of coding and capturing of all perforation diagnoses may possibly be deficient. CONCLUSION The risk of perforation from a colonoscopy is low, but, despite increased experience with the procedure, it remains unchanged over time.
The American Journal of Medicine | 2014
Uri Ladabaum; Ajitha Mannalithara; Parvathi A. Myer; Gurkirpal Singh
BACKGROUND Obesity and abdominal obesity are associated independently with morbidity and mortality. Physical activity attenuates these risks. We examined trends in obesity, abdominal obesity, physical activity, and caloric intake in US adults from 1988 to 2010. METHODS Univariate and multivariate analyses were performed using National Health and Nutrition Examination Survey data. RESULTS Average body mass index (BMI) increased by 0.37% (95% confidence interval [CI], 0.30-0.44) per year in both women and men. Average waist circumference increased by 0.37% (95% CI, 0.30-0.43) and 0.27% (95% CI, 0.22-0.32) per year in women and men, respectively. The prevalence of obesity and abdominal obesity increased substantially, as did the prevalence of abdominal obesity among overweight adults. Younger women experienced the greatest increases. The proportion of adults who reported no leisure-time physical activity increased from 19.1% (95% CI, 17.3-21.0) to 51.7% (95% CI, 48.9-54.5) in women, and from 11.4% (95% CI, 10.0-12.8) to 43.5% (95% CI, 40.7-46.3) in men. Average daily caloric intake did not change significantly. BMI and waist circumference trends were associated with physical activity level but not caloric intake. The associated changes in adjusted BMIs were 8.3% (95% CI, 6.9-9.6) higher among women and 1.7% (95% CI, 0.68-2.8) higher among men with no leisure-time physical activity compared with those with an ideal level of leisure-time physical activity. CONCLUSIONS Our analyses highlight important dimensions of the public health problem of obesity, including trends in younger women and in abdominal obesity, and lend support to the emphasis placed on physical activity by the Institute of Medicine.
Annals of the Rheumatic Diseases | 2008
Eiichi Tanaka; Ajitha Mannalithara; Eisuke Inoue; Masako Hara; Taisuke Tomatsu; Naoyuki Kamatani; Gurkirpal Singh; Hisashi Yamanaka
Objectives: The aim of this study was to examine the effect of efficient management of rheumatoid arthritis (RA) in relation to disability levels in a large cohort of patients with RA over a period of 3 years. Methods: We studied 2775 patients with RA who had continuous enrolment for at least 3 years from 7511 patients with RA enrolled in an observational cohort study (Institute of Rheumatology, Rheumatoid Arthritis (IORRA)) from October 2000 to April 2005. The 28-joint Disease Activity Scores (DAS28) were calculated at 6 month intervals for all the patients and a value <2.6 was considered as a tight control. We have set up a new variable for each patient, “Avg-Dscore”, based on the transition of each patient’s DAS28 value, taking the threshold level of 2.6 into consideration. The “Avg-DAS28” is the average of DAS28 values over all the phases. Functional disability status was assessed by J-HAQ, the validated Japanese version of the Health Assessment Questionnaire (HAQ). The relationship of “Avg-Dscore” and “Avg-DAS28” with the functional disability level was determined using Spearman correlation coefficients and multiple linear regression models. Results: The baseline features of these 2775 patients were: female 83.7%, mean age 56.8 years, mean RA duration 9.5 years, mean initial DAS28 4.0, mean initial J-HAQ score 0.79, and mean final J-HAQ score 0.86. There was a statistically significant correlation between “Avg-DAS28” and final J-HAQ score (r = 0.57, p<0.001), indicating that tighter disease control has significant association with lower disability levels. A similar relationship was observed between “Avg-Dscore” and final J-HAQ score (r = 0.47, p<0.001). Multiple linear regression analysis, after adjusting for all the covariates, revealed that “Avg-Dscore” and “Avg-DAS28” were the most significant factors contributing to final J-HAQ score, and confirmed the strong relationship between disease activity and functional disability. Conclusions: In patients with RA efficient disease management, by maintaining the DAS28 values at a level under 2.6, has significant association with improving functional capability. The threshold DAS28 level of 2.6 may be useful in developing targeted treatment guidelines for patients with RA.
Clinical Gastroenterology and Hepatology | 2012
Uri Ladabaum; Erin Boyd; Wei K. Zhao; Ajitha Mannalithara; Annie Sharabidze; Gurkirpal Singh; Elaine Chung; Theodore R. Levin
BACKGROUND & AIMS Irritable bowel syndrome (IBS) imposes significant clinical and economic burdens. We aimed to characterize practice patterns for patients with IBS in a large health maintenance organization, analyzing point of diagnosis, testing, comorbidities, and treatment. METHODS Members of Kaiser Permanente Northern California who were diagnosed with IBS were matched to controls by age, sex, and period of enrollment. We compared rates of testing, comorbidities, and interventions. RESULTS From 1995-2005, IBS was diagnosed in 141,295 patients (mean age, 46 years; standard deviation, 17 years; 74% female). Internists made 68% of diagnoses, gastroenterologists 13%, and others 19%. Lower endoscopy did not usually precede IBS diagnosis. Patients with IBS were more likely than controls to have blood, stool, endoscopic, and radiologic tests and to undergo abdominal or pelvic operations (odds ratios, 1.5-10.7; all P < .0001). Only 2.7% were tested for celiac disease, and only 1.8% were eventually diagnosed with inflammatory bowel disease. Chronic pain syndromes, anxiety, and depression were more common among IBS patients than among controls (odds ratios, 2.7-4.6; all P < .0001). Many patients with IBS were treated with anxiolytics (61%) and antidepressants (55%). Endoscopic and radiologic testing was most strongly associated with having IBS diagnosed by a gastroenterologist. Psychotropic medication use was most strongly associated with female sex. CONCLUSIONS In a large, managed care cohort, most diagnoses of IBS were made by generalists, often without endoscopic evaluation. Patients with IBS had consistently higher rates of testing, chronic pain syndromes, psychiatric comorbidity, and operations than controls. Most patients with IBS were treated with psychiatric medications.
The American Journal of Gastroenterology | 2013
Parvathi A. Myer; Ajitha Mannalithara; Gurjot Singh; Gurkirpal Singh; Pankaj J. Pasricha; Uri Ladabaum
OBJECTIVES:Gastrointestinal (GI) emergencies may cause substantial morbidity. Our aims were to characterize the national clinical and economic burden of GI visits to emergency departments (EDs) in the United States.METHODS:We performed an observational cross-sectional study using the 2007 Nationwide Emergency Department Sample, the largest US all-payer ED database, to identify the leading causes for ED visits due to GI diseases and their associated charges, stratified by age and sex. Logistic regression was used to analyze predictors of hospitalization after an ED visit.RESULTS:Of the 122 million ED visits in 2007, 15 million (12%) had a primary GI diagnosis. The leading primary GI diagnoses were abdominal pain (4.7 million visits), nausea and vomiting (1.6 million visits), and functional disorders of the digestive system (0.7 million visits). The leading diagnoses differed by age group. The fraction of ED visits resulting in hospitalization was 21.6% for primary GI diagnoses vs. 14.7% for non-GI visits. Women had more ED visits with a primary GI diagnosis than men (58.5 (95% CI 56.0–60.9) vs. 41.6 (95% CI 39.8–43.3) per 1000 persons), but lower rates of subsequent hospitalization (20.0% (95% CI 19.4–20.7%) vs. 24.0% (95% CI 23.3–24.6%)). There were no differences in hospitalization rates between sexes after adjustment by age, primary GI diagnosis, and Charlson Comorbidity Score. The total charges for ED visits with a primary GI diagnosis in 2007 were
Alimentary Pharmacology & Therapeutics | 2016
Joseph Ahn; Hannah Lee; Joseph K. Lim; Calvin Q. Pan; Mindie H. Nguyen; W. Ray Kim; Ajitha Mannalithara; Huy N. Trinh; Danny Chu; Tram T. Tran; Albert D. Min; Son T. Do; Helen S. Te; K. R. Reddy; Anna S. Lok
27.9 billion.CONCLUSIONS:GI illnesses account for substantial clinical and economic burdens on US emergency medical services.
Journal of Hepatology | 2016
Prowpanga Udompap; Ajitha Mannalithara; Nae Yun Heo; Donghee Kim; W. Ray Kim
Entecavir (ETV) has been shown to be safe and efficacious in randomised controlled trials in highly selected patients with hepatitis B virus (HBV) infection.
PLOS ONE | 2012
Gaurav Arora; Ajitha Mannalithara; Alka Mithal; George Triadafilopoulos; Gurkirpal Singh
BACKGROUND & AIMS Cirrhosis from hepatitis C virus (HCV) infection is a major cause of end-stage liver disease and hepatocellular carcinoma worldwide. We determine the prevalence of cirrhosis among HCV-infected American adults including those unaware of their infection. METHODS Using the National Health and Nutrition Examination Survey (NHANES) data, we identified participants aged ⩾20 years with detectable serum HCV RNA. The prevalence of advanced fibrosis and cirrhosis was determined for eras 1 (1988-94), 2 (1999-2006) and 3 (2007-2012) by using FIB-4 >3.25 and APRI >2.0, respectively. RESULTS Out of 52,644 NHANES examinees, 49,429 were tested for HCV, of whom 725 met the inclusion criteria (positive HCV RNA with available data for FIB-4 and APRI). Based on APRI, 6.6% (95% confidence interval [CI]: 2.2-11.0) of HCV-infected adults in era 1, 7.6% (95% CI: 3.4-11.8) in era 2 and 17.0% (95% CI: 8.0-26.0) in era 3 had cirrhosis. In the multivariable regression analysis, this era effect was attributable to increasing age (odds ratio [OR]:1.04, 95% CI: 1.02-1.07), diabetes (OR: 2.33, 95% CI: 1.01-5.40) and obesity (OR: 2.96, 95% CI: 1.15-7.57). Cirrhosis was as common among respondents who were unaware of their infection as those who were aware (both 11%). Results were identical when FIB-4 was used. CONCLUSIONS Among HCV-infected American adults, the proportion with cirrhosis has increased rapidly. Cirrhosis prevalence remains high in individuals unaware of their HCV infection. These data highlight the urgency for HCV screening regardless of symptoms, systematic assessment for liver fibrosis in those with HCV infection and institution of antivirals to prevent advanced liver disease. LAY SUMMARY Chronic hepatitis C virus (HCV) infection is a major cause of cirrhosis, creating a large public health burden. Based on the U.S. National Health and Nutrition Examination Survey sample, we found the proportion of patients with cirrhosis among Americans with HCV infection increased from 6.6% to 17.0% over the past two decades. Patients who were unaware of their infection were just as likely to have cirrhosis as those who knew about their infection, which highlights the need for screening and treatment for HCV at the population level.
Cancer | 2015
Uri Ladabaum; Ajitha Mannalithara; Lina Jandorf; Steven H. Itzkowitz
Background Chronic constipation (CC) is a common condition but its concurrent conditions are not well characterized. We measured the prevalence and risk of developing 15 pre–specified concurrent conditions in patients with CC. Methods Retrospective cohort study using the Medicaid database of California, utilizing ICD-9 codes for detection of cases (CC), controls (patients with GERD) and concurrent conditions. Study period was 01/01/1995 to 06/30/2005. Index date was the date 3 months before the first physician visit for CC. Pre-index time (12 months) was compared to post-index time (12 months) to assess the association of every concurrent condition within each cohort. To account for ascertainment bias, an adjusted odds ratio was calculated by comparing the odds ratio for every concurrent condition in the CC cohort to that in the GERD cohort. Results 147,595 patients with CC (mean age 54.2 years; 69.7% women; 36.2% white) and 142,086 patients with GERD (mean age 56.3 years; 65.3% women; 41.6% white) were evaluated. The most prevalent concurrent conditions with CC were hemorrhoids (7.6%), diverticular disease (5.9%), ano–rectal hemorrhage (4.7%), irritable bowel syndrome (3.5%) and fecal impaction (2%). When adjusted for ascertainment bias, the most notable associations with CC were Hirschsprungs disease, fecal impaction and ano-rectal conditions such as fissure, fistula, hemorrhage and ulcers. Conclusion Chronic constipation is associated with several concurrent conditions of variable risk and prevalence. To reduce the overall burden of CC, these concurrent conditions need to be addressed.
The American Journal of Gastroenterology | 2014
Uri Ladabaum; Christina A. Clarke; David J. Press; Ajitha Mannalithara; Parvathi A. Myer; Iona Cheng; Scarlett Lin Gomez
Colorectal cancer (CRC) screening is underused by minority populations, and patient navigation increases adherence with screening colonoscopy. In this study, the authors estimated the cost‐effectiveness of navigation for screening colonoscopy from the perspective of a payer seeking to improve population health.