The epidemiology of osteonecrosis: findings from the GPRD and THIN databases in the UK.

UNLABELLED: We conducted a case-control study to examine osteonecrosis (ON) incidence, patient characteristics, and selected potential risk factors using two health record databases in the UK. Statistically significant risk factors for ON included systemic corticosteroid use, hospitalization, referral or specialist visit, bone fracture, any cancer, osteoporosis, connective tissue disease, and osteoarthritis. INTRODUCTION: The purpose of this case-control study was to examine the incidence of osteonecrosis (ON), patient characteristics, and selected potential risk factors for ON using two health record databases in the UK: the General Practice Research Database and The Health Improvement Network. METHODS: ON cases (n = 792) were identified from 1989 to 2003 and individually matched (age, sex, and medical practice) up to six controls (n = 4,660) with no record of ON. Possible risk factors were considered for inclusion based on a review of published literature. Annual incidence rates were computed, and a multivariable logistic regression model was derived to evaluate selected risk factors. RESULTS: ON of the hip represented the majority of cases (75.9%). Statistically significant risk factors for ON were systemic corticosteroid use in the previous 2 years, hospitalization, referral or specialist visit, bone fracture, any cancer, osteoporosis, connective tissue disease, and osteoarthritis within the past 5 years. Only 4.4% of ON cases were exposed to bisphosphonates within the previous 2 years. CONCLUSIONS: This study provides further perspective on the descriptive epidemiology of ON. Studies utilizing more recent data may further elucidate the understanding of ON key predictors.

Postmarketing surveillance of new food ingredients: design and implementation of the program for the fat replacer olestra.

Following U.S. Food and Drug Administration (FDA) approval for the use of olestra, a noncaloric fat substitute (brand name Olean) in food snacks, the manufacturer agreed to provide safety updates on market experience to the FDA. However, guidelines for food product postmarketing surveillance (PMS) are not available and those typically used with medical products were only partly applicable. In modeling the Olean program, we drew from experience with consumer products and incorporated elements typical of medical product PMS. A cooperative effort was established with Olean snack manufacturers and a two-tiered, multidisciplinary approach enlisting Consumer Relations and Medical Affairs personnel was used to maximize use of specialized skills. The result of this effort was implementation of a reliable PMS system which could handle a high volume of reports from consumers while providing pertinent data required for medical interpretation of these reports. Summaries of data for the Olean snack manufacturers and FDA were generated in timely fashion. In addition to collection of the spontaneous reports from consumers, a clinical studies program was undertaken and an independent medical advisory panel was established. Through these, we gained perspective on the spontaneous reports and additional confirmation of the safety of olestra in savory snacks.

Gastrointestinal symptoms in 3181 volunteers ingesting snack foods containing olestra or triglycerides. A 6-week randomized, placebo-controlled trial.

BACKGROUND: Olestra is a nonabsorbable, energy-free fat substitute. Because it is not absorbed, it may cause digestive symptoms when consumed in large amounts. OBJECTIVE: To compare the frequency and impact of gastrointestinal symptoms in adults and children who freely consume snacks containing olestra or regular snacks in the home. DESIGN: 6-week, double-blind, randomized, parallel, placebo-controlled trial. SETTING: General community. PARTICIPANTS: 3181 volunteers 2 to 89 years of age. INTERVENTION: Households received identical packages labeled as containing olestra corn or potato chips. These packages contained either olestra or regular chips (control). MEASUREMENT: Gastrointestinal symptoms and their impact on daily activities were reported in a daily record. RESULTS: At least one gastrointestinal symptom was reported by 619 of 1620 (38.2%) persons in the olestra group and 576 of 1561 (36.9%) controls (difference, 1.3 percentage points [95% CI, -3.6 to 6.2 percentage points]; P = 0.60). In general, the groups did not differ significantly in the proportion of participants who reported individual gastrointestinal symptoms; however, more controls reported nausea (8.4% compared with 5.7%; difference, -2.7 percentage points [CI, -4.9 to -0.4 percentage points]; P = 0.02). The only difference between groups for the mean numbers of days on which symptoms were reported was that participants in the olestra group had 1 more symptom-day of more frequent bowel movements than did controls (3.7 symptom-days compared with 2.8 symptom days; difference, 0.9 symptom-days [CI, 0.1 to 1.8 symptom-days]; P = 0.04). The groups did not differ in the impact of symptoms on daily activities. CONCLUSIONS: Clinically meaningful or bothersome gastrointestinal effects are not associated with unregulated consumption of olestra corn and potato chips in the home.

Gastrointestinal symptoms following consumption of olestra or regular triglyceride potato chips: a controlled comparison.

CONTEXT: Olestra, a nonabsorbable, energy-free fat substitute used in snack foods, has been anecdotally reported to cause gastrointestinal (GI) adverse events, although such effects were not expected based on results from randomized trials, in which it was consumed in typical snack patterns. OBJECTIVE: To determine whether ad libitum consumption of potato chips made with the fat substitute olestra results in a different level of GI symptoms than regular chips made with triglyceride (TG). DESIGN: Randomized, double-blind, parallel, placebo-controlled trial. SETTING: A suburban Chicago, III, multiplex cinema. SUBJECTS: A total of 1123 volunteers aged 13 to 88 years. INTERVENTION: Subjects were given a beverage and an unlabeled, white 369-g (13-oz) bag of potato chips made with olestra or TG during a free movie screening. MAIN OUTCOME MEASURES: Total and specific GI symptoms reported during a telephone interview conducted from 40 hours to 10 days after ingestion; level of potato chip consumption; and satiety level. RESULTS: Of 563 evaluable subjects in the olestra chip group, 89 (15.8%) reported 1 or more GI symptoms, while 93 (17.6%) of the 529 evaluable subjects in the regular TG chip group did so (difference in symptom frequency between olestra and TG, -1.8; 95% confidence interval, -6.2 to 2.7; P=.47). For specific GI symptoms (eg, gas, diarrhea, abdominal cramping), there were no significant differences between olestra and TG chips. Fewer olestra chips were consumed than TG chips (60 vs 77 g [2.1 vs 2.7 oz]; P<.001), with olestra chips receiving lower taste scores (5.6 vs 6.4 on a 9-point scale; P<.001). Consumption levels did not correlate with the rate of symptom reporting in either the olestra or TG group. There was no difference in satiety scores between olestra and TG chips (5.7 vs 5.9 on a 9-point scale; P=.07). CONCLUSIONS: This study demonstrates that ad libitum consumption of olestra potato chips during 1 sitting is not associated with increased incidence or severity of GI symptoms, nor does the amount consumed predict who will report GI effects after short-term consumption of either olestra or TG potato chips.

Toxic shock syndrome: incidence and geographic distribution from a hospital medical records reporting system.

A large database of hospital records maintained by the Commission on Professional and Hospital Activities Professional Activity Study (CPHA-PAS) was used to estimate the temporal incidence and geographic distribution of toxic shock syndrome (TSS). The CPHA-PAS hospital-diagnosed incidence was 3.5 times the reported TSS incidence, with a gradual decrease over the time period 1981-83. Marked differences in the regional occurrence of cases may provide clues to the etiology of this complex disease.

A peripheral vascular insufficiency test using photocell plethysmography.

A preliminary laboratory study seeking an objective test for vascular insufficiency of the fingertips (Raynaud's syndrome) is described. In a limited number of subjects, circulatory changes in the vascular bed of one hand were examined by photocell plethysmography while the opposite had was immersed in ice water. The time to complete recovery after cessation of the cold stimulus was significantly longer with primary Raynaud's patients than with the control subjects (p = 0.0045). The analysis of another parameter, the relative change in pulse amplitude during cold immersion, was confounded by age and sex differences between the Raynaud's and the control group. A follow-up investigation of the application of this technique to a population of vibration-exposed chipper and grinder and control workers is in progress.

Chlorine dioxide water disinfection: a prospective epidemiology study.

An epidemiologic study of 198 persons exposed for 3 months to drinking water disinfected with chlorine dioxide was conducted in a rural village. A control population of 118 nonexposed persons was also studied. Pre-exposure hematologic and serum chemical parameters were compared with test results after 115 days of exposure. Statistical analysis (ANOVA) of the data failed to identify any significant exposure-related effects. This study suggests that future evaluations of chlorine dioxide disinfection should be directed toward populations with potentially increased sensitivity to hemolytic agents.