James Allison

University of California, San Francisco, San Francisco, CA, USA

Are you James Allison?

Claim your profile

Publications (4)29.45 Total impact

  • Article: Natural history of severe ulcerative colitis in a community-based health plan.
    [show abstract] [hide abstract]
    ABSTRACT: We sought to evaluate long-term outcomes of patients with severe ulcerative colitis (UC) after their first hospitalization for the disease. A cohort of 656 patients hospitalized for UC during 1996 to 2004 was followed up for 9 years through 2004. Time-to-event was estimated using actuarial methods, and the proportions of those under follow-up evaluation who experienced outcomes at month 3, year 1, and year 5 were determined. Outcome measures studied were time to subsequent colectomy, rehospitalization for inflammatory bowel disease, and restarting steroid medication. We also used survival analysis to evaluate whether patient characteristics predicted the risk of rehospitalization and colectomy. Among 656 patients initially hospitalized for severe UC, 20% (N = 129) underwent colectomy during their initial hospitalization. Of the remaining 527, a total of 95% (N = 498) were discharged on a steroid taper. At 1 year after discharge, 29% of those remaining under observation were rehospitalized for UC, and an additional 10% required colectomy. At 1 and 5 years after discharge, 34% and 26% received at least a 90-day supply of steroid in the preceding 9 months. Risk of rehospitalization and colectomy were unrelated to the patient's age, sex, or race/ethnicity. The risk for colectomy in patients hospitalized for the first time with severe UC is 20%. In the 3 months after hospitalization the risk for colectomy is 6%. After that, risks appear to decrease proportionate to the time since initial hospitalization.
    Clinical gastroenterology and hepatology: the official clinical practice journal of the American Gastroenterological Association 10/2008; 6(9):999-1003. · 5.64 Impact Factor
  • Article: Incidence and prevalence of inflammatory bowel disease in a Northern California managed care organization, 1996-2002.
    [show abstract] [hide abstract]
    ABSTRACT: There are few estimates of the incidence and prevalence of inflammatory bowel disease in North American communities. We sought to estimate the incidence and prevalence of inflammatory bowel disease (IBD), including Crohn's disease (CD), and ulcerative colitis (UC), among 3.2 million members of Kaiser Permanente, Northern California, for the period 1996-2002. All health plan members who had one or more diagnoses of CD (ICD-9 code 555) or UC (ICD-9 code 556) on computerized records during the period 1996-2002 and with at least 12 months of membership were identified as possible IBD cases (N = 12,059). We randomly sampled 24% of these for chart review to confirm the diagnosis and obtain the initial diagnosis date. Incidence rates and the point prevalence on December 31, 2002 were standardized to the 2000 U. S. Census. The annual incidence rate per 100,000 persons was 6.3 for CD (95% confidence interval [CI], 5.6-7.0) and 12.0 for UC (CI, 11.0-13.0). The point prevalence per 100,000 on December 31, 2002 was 96.3 for CD (95% CI, 89.6-103.0) and 155.8 for UC (95% CI, 146.6-164.9), increasing to 100.3 and 205.8 per 100,000, respectively, when hospital discharge data from 1985 to 1995 were included. The age-specific incidence of CD was bimodal, while UC incidence rose in early adulthood and remained elevated with advancing age. The incidence we estimated for CD was similar to the previous U. S. estimate. Our incidence estimate for UC was much higher than the previous U.S. estimate, but similar to that of recent Canadian and European studies. The prevalence we estimated for CD was somewhat lower than previous estimates.
    The American Journal of Gastroenterology 09/2008; 103(8):1998-2006. · 7.28 Impact Factor
  • Article: Patterns of infliximab use among Crohn's disease patients in a community setting.
    [show abstract] [hide abstract]
    ABSTRACT: Information on infliximab use in a community setting is important to understand patterns of medication use and to anticipate and plan for costs associated with the drug. We sought to understand predictors of initiation and discontinuation of infliximab in the community-based setting of Kaiser Permanente, Northern California, which provides integrated care to its members. The cohort study was set during 1998-2006. Predictors of initiation were assessed among 494 Crohn's disease (CD) patients who initiated infliximab and 2470 CD patients who did not initiate infliximab (controls). Data were obtained through linkage of computerized clinical information and were analyzed using logistic regression and Cox survival analysis. Infliximab infusions have increased rapidly since 2001, with no evidence of leveling off. Initiators were appreciably younger than controls (P < 0.001), but were similar to controls with respect to sex and race/ethnicity. The presence of at least 1 comorbidity was related to a modest increase in the risk of initiating (compared with none: 1 comorbidity, odds ratio [OR] = 1.52 with 95% confidence interval [CI] 1.16-2.00; 2 comorbidities, OR = 1.38 with CI 0.89-2.13). By 3 years after initiating, only 20% of patients remained on infliximab. In a community-based setting infliximab use has steadily increased. Age and comorbidity are associated with initiation, but sex and race/ethnicity are not. More information is needed to determine why, in this community-based setting, a large number of patients on infliximab discontinued their treatment.(Inflamm Bowel Dis 2008).
    Inflammatory Bowel Diseases 05/2008; 14(9):1265-72. · 4.86 Impact Factor
  • Article: Mortality by medication use among patients with inflammatory bowel disease, 1996-2003.
    [show abstract] [hide abstract]
    ABSTRACT: Most previous population-based studies of mortality in inflammatory bowel disease (IBD) did not account for medication use. We evaluated mortality by IBD medication use among members of the Kaiser Permanente Northern California IBD Registry. The retrospective, population-based cohort study included 9032 persons who received at least one inpatient or 2 outpatient diagnoses of IBD during 1996-2002. Age and sex standardized mortality ratios measured the associations between IBD and all-cause and cause-specific mortality. Age, sex, and smoking adjusted odds ratios measured the association of mortality by IBD medication use. Compared with health plan members without IBD, mortality was increased in patients with Crohn's disease (CD) (1.4; 95% confidence interval, 1.2-1.6) but not ulcerative colitis (UC) (1.0; 95% CI, 0.9-1.2). CD was associated with increased mortality from infectious and parasitic diseases (4.1; 95% CI, 1.7-8.5), septicemia (6.8; 95% CI, 2.2-15.8), small intestinal cancer (48.1; 95% CI, 5.8-17.4), respiratory diseases (1.9; 95% CI, 1.3-2.7), digestive diseases other than IBD (2.4; 95% CI, 1.0-4.8), and liver diseases (2.6; 95% CI, 1.0-5.3). UC was associated with increased mortality from digestive diseases other than IBD (3.9; 95% CI, 2.4-6.0). The relationship with CD mortality was 0.7 for aminosalicylates (95% CI, 0.5-1.1), 1.3 (95% CI, 0.9-1.9) for immunomodulators, and 1.0 (95% CI, 0.7-1.4) for corticosteroids. Among patients with UC, these odds ratios were 0.8 (95% CI, 0.5-1.1) for aminosalicylates, 0.5 (95% CI, 0.3-0.9) for immunomodulators, and 0.8 (95% CI, 0.6-1.1) for corticosteroids. Mortality is increased in CD. Infections, respiratory diseases, and digestive diseases are important specific causes of death. IBD medication use has varying associations with mortality.
    Gastroenterology 12/2007; 133(6):1779-86. · 11.68 Impact Factor