Enteric pathogens and reactive arthritis: a systematic review of Campylobacter, salmonella and Shigella-associated reactive arthritis.

Reactive arthritis (ReA) is a spondyloarthropathic disorder characterized by inflammation of the joints and tissues occurring after gastrointestinal or genitourinary infections. Diagnostic criteria for ReA do not exist and, therefore, it is subject to clinical opinion resulting in cases with a wide range of symptoms and definitions. Using standardized diagnostic criteria, we conducted a systematic literature review to establish the global incidence of ReA for each of the three most commonly-associated enteric pathogens: Campylobacter, Salmonella, and Shigella. The weighted mean incidence of reactive arthritis was 9, 12, and 12 cases per 1,000 cases of Campylobacter, Salmonella and Shigella infections respectively. To our knowledge, this is the first systematic review of worldwide data that use well-defined criteria to characterize diarrhoea-associated ReA. This information will aid in determining the burden of disease and act as a planning tool for public-health programmes.

Social determinants of mixed feeding behavior among HIV-infected mothers in Jos, Nigeria.

Mixed feeding confers excess risk of mother-to-child transmission (MTCT) of HIV compared with exclusive breastfeeding and exclusive formula feeding. We undertook a qualitative and quantitative cross-sectional survey to identify the social determinants of mixed feeding among a subset of the 469 HIV-infected women enrolled in a MTCT prevention program in Jos, Nigeria. Formula was provided free-of-cost. Of the 91 participants, 68 (75%) exclusively formula fed, 7 (8%) exclusively breastfed, and 16 (18%) practiced mixed feeding. Of the mixed feeding women, seven primarily formula fed and nine primarily breastfed. Women who primarily formula fed described family pressure as the reason for mixed feeding, while women who primarily breastfed reported insufficient breast milk. In a multivariate analysis, lack of partner support of the feeding decision predicted mixed feeding behavior (OR: 4.2; 95% CI: 1.2-14.9; p=0.03). Disclosure of HIV status was significantly correlated (p<0.001) with partner support. HIV prevention interventions aimed at reducing mixed feeding should encourage supportive partner relationships that facilitate disclosure of HIV status. Attention should also be made to the differing pressures faced by women attempting to exclusively breast feed and exclusively formula feed.

Timing and determinants of mother-to-child transmission of HIV in Nigeria.

OBJECTIVE: To characterize the timing and determinants of mother-to-child transmission (MTCT) of HIV among mothers receiving single-dose nevirapine to prevent MTCT in Nigeria. METHODS: Three hundred and seventy-one HIV-infected mothers and their infants were followed from birth, at 1 week, and at 1, 3, 6, and 12 months. Risks of in utero (IU), intrapartum (IP/EPP), and postnatal (PP) transmission were quantified using conditional Cox regressions. RESULTS: Maternal viral load was the only risk factor for IU transmission after controlling for known risk factors. Low birth weight, premature birth, mixed feeding, and maternal viral load were associated with IP/EPP transmission. Increased PP transmission was associated with low birth weight and mixed feeding. At 6 months, mixed-fed infants were more likely to acquire infection than formula-fed infants (hazard ratio=5.74; 95% CI, 1.26-26.2). CONCLUSION: Risk factors for IU transmission differed from those of IP and PP transmission. Reducing mixed feeding and low birth weight delivery among HIV-infected mothers can further decrease IP and PP transmission.

Algorithms to identify colonic ischemia, complications of constipation and irritable bowel syndrome in medical claims data: development and validation.

PURPOSE: A challenge in the use of insurance claims databases for epidemiologic research is accurate identification and verification of medical conditions. This report describes the development and validation of claims-based algorithms to identify colonic ischemia, hospitalized complications of constipation, and irritable bowel syndrome (IBS). METHODS: From the research claims databases of a large healthcare company, we selected at random 120 potential cases of IBS and 59 potential cases each of colonic ischemia and hospitalized complications of constipation. We sought the written medical records and were able to abstract 107, 57, and 51 records, respectively. We established a 'true' case status for each subject by applying standard clinical criteria to the available chart data. Comparing the insurance claims histories to the assigned case status, we iteratively developed, tested, and refined claims-based algorithms that would capture the diagnoses obtained from the medical records. We set goals of high specificity for colonic ischemia and hospitalized complications of constipation, and high sensitivity for IBS. RESULTS: The resulting algorithms substantially improved on the accuracy achievable from a naïve acceptance of the diagnostic codes attached to insurance claims. The specificities for colonic ischemia and serious complications of constipation were 87.2 and 92.7%, respectively, and the sensitivity for IBS was 98.9%. CONCLUSIONS: U.S. commercial insurance claims data appear to be usable for the study of colonic ischemia, IBS, and serious complications of constipation.

Neoplasms in the Navy, 1998-2000: a descriptive analysis of the Physical Evaluation Board database.

Records with diagnoses for neoplasms (International Classification of Diseases, Ninth Revision, Clinical Modification, codes 140-239) contained in the U.S. Navy Physical Evaluation Board database for 1998 to 2000 were identified (n = 427 cases, 342 malignant and 85 benign). The four most common sites of occurrence were other and unspecified sites (27%), lymphatic and hematopoietic tissues (22%), benign neoplasms (20%), and genitourinary organs (12%). Crude overall cancer rates were 37.7 cases per 100,000 male subjects and 55.4 cases per 100,000 female subjects. Overall, Hodgkin's disease was the most common diagnosis, with a rate of 3.3 cases per 100,000 population. It also had the highest rate among male subjects, with 3.5 cases per 100,000 male subjects of all ages and 4.2 cases per 100,000 men more than 40 years of age. For women, breast cancer had the highest rate of 8.5 cases per 100,000 subjects. These values are consistent with or lower than the published reports of U.S. Navy and national rates. Ongoing surveillance of malignancies among Navy personnel is an important part of force health protection.

Risk factors for colon ischemia.

BACKGROUND: To identify predictors of colon ischemia, we examined demographic and clinical characteristics of patients, as well as their prior health care utilization. METHODS: Using insurance data, we identified 700 persons at least 20-yr old with presumed colon ischemia between 1995 and 1999, and 6,440 controls. Case identification was based on diagnosis and procedure codes in insurance claims for which we used a previously reported, validated algorithm. We ascertained preceding medical diagnoses and the use of drugs and health services from the insurance claims files. RESULTS: Patients with colon ischemia were nearly three times as likely to have IBS than controls. A history of nonspecific colitis, lower gastrointestinal tract hemorrhage, systemic rheumatologic disorders, and ischemic heart disease in the preceding 6 months, and abdominal surgery in the past month were also much more common in colon ischemia cases than controls. Use of a drug to treat diarrhea was strongly associated with risk. The most prevalent risk factor for colon ischemia was the use of drugs with a side effect of constipation, found in one-third of cases and one in nine controls. Cases had seen physicians, particularly gastroenterologists, much more commonly in the preceding 6 months than had controls. CONCLUSIONS: Clinically evident colon ischemia arises preferentially in persons with prior abdominal complaints, many of whom carry a diagnosis of IBS. Drugs that reduce bowel motility may constitute a widespread and potentially avoidable risk factor. The frequency of preceding doctor visits, without a specific diagnosis, suggests that colon ischemia may have a prolonged subacute presentation.

Occurrence of colon ischemia in relation to irritable bowel syndrome.

OBJECTIVE: In November 2000, alosetron HCl (Lotronex), a treatment for irritable bowel syndrome (IBS), was removed from the U.S. market in part because of the occurrence of colon ischemia in treated patients. Since the relation between colon ischemia and IBS is poorly understood, we evaluated the incidence of colon ischemia among people with and without IBS. METHODS: Using medical claims data from a large health care organization in the United States, we identified 87,449 people with an IBS diagnosis between January 1995 and December 1999. We calculated age- and sex-specific incidence rates in the general population and in IBS patients. RESULTS: There were 740 cases of colon ischemia during 8.5 million person-years of observation in 5.4 million persons. The crude incidence rate was 42.8 cases per 100,000 person-years for IBS patients. By comparison, the incidence rate was 7.2 per 100,000 person-years in the general population. After adjustment for age, sex, and calendar year, the incidence of colon ischemia in people with IBS was 3.4 times higher than in persons without (95% CI 2.6-4.5). CONCLUSIONS: Rates of colon ischemia among patients carrying a diagnosis of IBS are substantially higher than in the general population. Colon ischemia, though unusual in IBS patients, may nonetheless constitute a distinct part of the IBS natural history. Alternatively, it may be a consequence of therapy, or a manifestation of other bowel pathology that is sometimes confused with IBS.

Risk for respiratory events in a cohort of patients receiving inhaled zanamivir: a retrospective study.

BACKGROUND: Inhaled zanamivir is indicated for treatment of uncomplicated acute illness due to influenza A and B viruses in patients aged > or = 12 years who have been symptomatic for no more than 2 days. OBJECTIVE: The primary objective of this study was to estimate the incidence of adverse respiratory events among zanamivir-treated patients under conditions of usual care. METHODS: The Ingenix research database includes insurance claims for all dispensations, inpatient and outpatient services, and procedures including the associated diagnoses and costs for a subset of all enrolled UnitedHealthcare members. We identified all persons with a dispensation of zanamivir recorded between October 1, 1999, and April 30, 2000. We captured medical and pharmaceutical claims data for the 6 months before the dispensation to obtain information about comorbidities, overall health status, and respiratory events. Medical and hospital record abstraction and clinical review served to confirm inpatient/emergency department (ED) events. We also examined the records of an approximately 10% random sample of patients treated for a potential respiratory event in an outpatient/ physician office visit during the 10-day follow-up period. Respiratory events not sufficiently severe to result in medical care were not captured in this study. RESULTS: A total of 5498 eligible zanamivir dispensations contributed by 5450 patients (2911 females, 2539 males; mean age, 38.8 years), with 40 confirmed inpatient/ED respiratory events, were included in the study. Of these 40 events, 31 were pneumonia, bronchitis, or exacerbations of existing chronic respiratory disease; none required intubation or ventilation. No events occurred on the dispensation date. The overall risk for an inpatient/ ED respiratory event was 0.7 per 100 episodes (95% CI, 0.5-1.0). Seven events of wheezing or shortness of breath were not an obvious extension of the original influenza-like illness or of a complicating bronchitis (risk = 0.13 per 100 episodes; 95% CI, 0.06-0.26). CONCLUSIONS: No immediate or severe bronchoconstrictive responses occurred among 5498 zanamivir dispensations. The overall risk for any respiratory event was low, and none was sufficiently severe to suggest respiratory failure.

The effect of zanamivir treatment on influenza complications: a retrospective cohort study.

BACKGROUND: Complications of influenza are a major cause of morbidity and mortality during the influenza season. Clinical trials of zanamivir have reported a reduced incidence of influenza complications among high-risk patients. OBJECTIVES: This retrospective study sought to determine whether the use of zanamivir lowers the risk of acute influenza complications in a broader population, based on an analysis of claims data from a large managed care organization. METHODS: Medical and pharmacy health insurance claims data from October 1, 1999, through April 30, 2000, were compiled for UnitedHealthcare members in 19 states. All patients with a diagnosis of influenza (International Classification of Diseases, Ninth Revision, Clinical Modification diagnostic code 487.xx) associated with a physician visit were identified. From these, all patients were selected who had received zanamivir on the same day as the diagnosis of influenza. The propensity score matching technique was used to identify a comparison group with similar health service utilization and comorbidities who received a diagnosis of influenza but no antiviral therapy. Follow-up started the day after the influenza diagnosis and continued for 21 days. RESULTS: From the 43,741 patients originally identified, 2341 were selected who received a simultaneous diagnosis of influenza and a prescription for zanamivir. The untreated comparator group numbered 2337. Fewer zanamivir patients than untreated patients were hospitalized for complications, and the absolute risks were low (0.6% and 1.0%, respectively; risk ratio [RR], 0.58; 95% CI, 0.30-1.12). Zanamivir-treated patients had an excess of outpatient visits (16.9% vs 14.5%; RR, 1.16; 95% CI, 1.02-1.33) and antibiotic use (16.3% vs 14.8%; RR, 1.10; 95% CI, 0.97-1.26), although the RRs were modest. CONCLUSIONS: In the setting of a large managed care plan, patterns of influenza complications were similar in zanamivir-treated and untreated patients with a diagnosis of influenza. The results of this study are in contrast to those of published clinical trials reporting a reduction in the risk of influenza complications in zanamivir-treated patients.