Group B streptococcal colonization and the risk of pre-eclampsia.

To determine if there was an association between recto-vaginal group B streptococcus (GBS) colonization and pre-eclampsia, two cross-sectional studies were conducted using statewide hospital databases. The first study analysed data from the state of Florida, USA, and included 190 645 women who were discharged in 2001. This dataset was used to generate the hypothesis that GBS colonization is associated with pre-eclampsia. The second study tested the GBS hypothesis using the records of 577 153 women who delivered in 2004 or 2005 in Texas, USA. Adjusted odds ratios (aOR) for the outcome of pre-eclampsia comparing GBS-positive to GBS-negative women were calculated using logistic regression. The aOR for the association between GBS carriage and pre-eclampsia was 0.71 [95% confidence interval (CI) 0.65-0.77] in the Florida dataset. In the Texas dataset, the overall prevalence of GBS carriage was 14.1% while the overall prevalence of pre-eclampsia was 4.0%. GBS carriers were 31% less likely than non-carriers to have pre-eclampsia (aOR 0.69, 95% CI 0.66-0.72) in Texas. In two large statewide analyses, GBS carriage was inversely associated with pre-eclampsia. A sensitivity analysis revealed that misclassification of GBS status is not a likely explanation of our findings.

Gastrointestinal symptomatology as a predictor of severe outcomes of invasive group A streptococcal infections.

Invasive group A streptococcal (GAS) disease is a condition of clinical and public health significance. We conducted epidemiological analyses to determine if the presence of gastrointestinal (GI) complaints (diarrhea and/or vomiting) early in the course of invasive GAS disease is associated with either of two severe outcomes: GAS necrotizing fasciitis, or hospital mortality. Subjects were hospitalized for invasive GAS disease throughout the state of Florida, USA, during a 4-year period. Multiple imputation using the Markov chain Monte Carlo method was used to replace missing values with plausible values. Excluding cases with missing data resulted in a sample size of 138 invasive GAS patients (the complete subject analysis) while the imputed datasets contained 257 records. GI symptomatology within 48 h of hospital admission was not associated with hospital mortality in either the complete subject analysis [adjusted odds ratio (aOR) 0.86, 95% confidence interval (CI) 0.31-2.39] or in the imputed datasets. GI symptoms were significantly associated with GAS necrotizing fasciitis in the complete subject analysis (aOR 4.64, 95% CI 1.18-18.23) and in the imputed datasets but only in patients aged <55 years. The common cause of GI symptoms and necrotizing fasciitis may be streptococcal exotoxins. Clinicians who are treating young individuals presumed to be in the early stages of invasive GAS disease should take note of GI symptoms and remain vigilant for the development of a GAS necrotizing soft-tissue infection.

A population-based epidemiologic analysis of deaths from anaphylaxis in Florida.

BACKGROUND: Previous US population-based epidemiologic studies of anaphylactic deaths have been limited by small populations and/or few deaths. The objective of this study was to determine the 10-year incidence of death from anaphylaxis in Florida and its descriptive epidemiology. METHODS: Patients who died from anaphylaxis from 1996 to 2005 were identified from ICD-9 and ICD-10 codes on death certificates statewide. Age, race and gender-specific anaphylactic death rates were calculated. RESULTS: There were 89 deaths among Florida residents. The individuals with autopsy confirmed diagnoses, and those with clinical diagnoses only, did not differ with regard to race, anaphylactic triggers or the clinical variables of lung and heart disease. Annual death rate for anaphylaxis in Florida was 5.02/10 000 000. The relative risk of death from anaphylaxis was 14.09 for individuals > or =65 years old (P = 0.0000002) and 6.38 for individuals 35-64 years old (P = 0.0019) compared with those who were 5-14 years of age. Deaths among Florida residents that occurred in emergency rooms or outpatient settings were 2.11 times as likely to be anaphylactic deaths than deaths that occurred in inpatient settings (P = 0.0026). The ratios of anaphylactic deaths to total deaths in March and April and in July and August were greater than the ratios for the other bimonthly periods (P = 0.02). CONCLUSION: Death from anaphylaxis in Florida was more likely to occur in older individuals, in an emergency department, and in the months of March and April and July and August.

Spline regression in clinical research.

OBJECTIVE: The objective of this article is to illustrate the statistical technique of spline regression, an under-utilized tool in clinical research. Spline regression was used to assess the dose-response association between serum albumin and hospital mortality. METHODS: Data from a previous study of patients hospitalized throughout Florida, United States of America (U.S.A.), for invasive group A streptococcal disease were accessed. For the current analysis, serum albumin (SA) at the time of admission was the risk factor of interest. The outcome was unadjusted hospital mortality among 117 patients. First, a traditional, suboptimal approach was employed by breaking SA into three groups and calculating the crude hospital mortality rate in each SA category. The second approach involved the creation of a curve using a quadratic spline model. RESULTS: The traditional approach yielded only three points of information: the hospital mortality rate for the three SA groups. Among patients whose SA upon admission was < 2.5 g/l00 mL, 2.5 to 3.4, and 3.5 or greater, the hospital mortality rate was 40.7%, 14.8%, and 8.3%, respectively. The spline model, however, resulted in a smooth curve which was more clinically plausible. CONCLUSION: The goal of this paper is to expose clinicians to splines. Spline regression, unlike categorical analysis, does not impose the unrealistic assumption of a homogenous risk within categories. Another disadvantage of categorical analyses is that they allow large changes in risk between categories,

Multiple sclerosis and breast cancer.

Multiple sclerosis (MS) and breast cancer (BC) share common features; most notably, both are more frequent in women than in men. In addition to the involvement of sex hormones, a number of genetic and pharmacological studies support a possible relationship between these two diseases. However, there are no conclusive epidemiological findings related to MS and BC worldwide, and there are no recent data for the US population. We conducted a case-control study using a hospital inpatient discharge dataset (21,536 cases and two control series totaling 59,581 controls) from the Texas Health Care Information Collection. We assessed occurrence of MS in BC cases and in two control series: diabetes mellitus type II, and open wounds. After controlling for age, race-ethnicity, and health insurance status, a statistically-significant protective association was detected: BC cases were 45% less likely than diabetic controls to have MS (OR=0.55, 95% CI=0.37-0.81), and 63% less likely than open wound controls to have MS (OR=0.37, 95% CI=0.21-0.66). Our study presented here is the only current assessment of the association between MS and BC in the USA and suggests a protective effect of MS on BC in the hospitalized population.

Primary malignancies of the thyroid: epidemiologic analysis of the Florida Cancer Data System registry.

PURPOSE: Descriptive epidemiology of thyroid cancer in Florida. METHODS: The Florida Cancer Data System (FCDS) registry was used to identify patients with the different histologic subtypes of thyroid cancer occurring in Florida from 1981 through 1993. RESULTS: The FCDS recorded 5746 primary malignancies of the thyroid. The average annual incidence of all types of thyroid cancer was 37.0 cases/1,000,000 population. One type of thyroid cancer (papillary carcinoma) accounted for the overall increase during the 13 years of this study. There was no difference in incidence based on Hispanic ethnicity, but the incidence in Blacks was half that of Whites, and Blacks showed less advanced disease at the time of diagnosis. CONCLUSIONS: The increase in incidence of only one histologic type of thyroid cancer suggests that the increasing rate is not an artifact related to the utilization of new diagnostic technologies. The lower incidence and tendency to have less advanced thyroid cancer in Blacks would indicate that racial differences in thyroid cancer are not likely explained by socioeconomic factors such as access to medical care. A substantial amount of the difference in incidence between Whites and Blacks is explained by differences in age distribution.

Malignant tumors of the eyelid: a population-based study of non-basal cell and non-squamous cell malignant neoplasms.

OBJECTIVE: To determine the relative frequencies, average annual incidences, and patient characteristics of non-basal cell and non-squamous cell malignant neoplasms of the eyelid in a defined geographic population. DESIGN AND SETTING: A retrospective study using the Florida Cancer Data System to identify malignant tumors of the eyelid, except for basal cell and squamous cell carcinomas, from 1981 through 1994. Cases were limited to persons who resided within Florida. MAIN OUTCOME MEASURE: Incidence of histologically confirmed malignant eyelid tumors. RESULTS: Two hundred six primary malignant eyelid tumors were identified. The 3 most common, in order of frequency, were melanoma, sebaceous carcinoma, and lymphoma. The median age at diagnosis for all patients was 73 years. Only 3 of the 206 malignant neoplasms occurred in blacks. The annual incidence of eyelid melanoma and sebaceous carcinoma in whites older than 20 years was 0.6 and 0.5 per million, respectively. Kaposi sarcoma was the most common type of mesenchymal tumor. Eleven different histologic types of lymphoma were found in the eyelid. Only 2 of 27 lymphomas had T-cell lineage. CONCLUSIONS: Malignant tumors of the eyelid other than basal cell and squamous cell carcinoma are uncommon and usually occur in elderly white persons. Primary eyelid tumors of any type are rare in blacks. The risk of a non-basal cell and non-squamous cell malignant neoplasm of the eyelid in Florida is 6.4 times greater for whites than for blacks (95% confidence interval [CI], 2.1-20.2). A variety of B-cell lymphomas can be manifested as primary eyelid tumors.

Correlates of length of stay, cost of care, and mortality among patients hospitalized for necrotizing fasciitis.

Several previous studies of necrotizing fasciitis (NF) have been single-institution investigations suffering from small samples sizes. This study of 216 NF patients hospitalized in Florida, USA, during 2001 was designed to identify risk factors for length of stay (LOS), total patient charges (TC), and mortality, using a statewide database. Robust gamma mixed regression was used to determine the predictors of LOS and TC while simultaneously accounting for outliers and the clustering of patients in 87 hospitals. Relative risks (RR) for hospital mortality were calculated using binomial regression. The NF hospitalization rate in Florida was 1.3/100,000. The median TC was US$54,533 and cumulative charges for all 216 patients were nearly US$20 million. Patients aged > or =44 years at the time of admission were five times as likely to expire in the hospital than patients who were aged < or =43 years (adjusted RR 5.08, P=0.03). Unexpectedly, diabetes was associated with a 61% reduction in the risk of hospital mortality (adjusted RR 0.39, P=0.04). Age > or =44 years was the most powerful predictor of prolonged LOS, elevated TC, and an increased risk of hospital mortality in patients suffering from NF.

Malignant tumors of the orbit. Analysis of the Florida Cancer Registry.

PURPOSE: The purpose of the study is to determine the relative frequency and incidence of primary malignant tumors of the orbit occurring in Florida. METHODS: Cases of primary orbital malignancy were identified in the Florida Cancer Data System registry from 1981 through 1993. Analysis was restricted to persons who reside within the state. RESULTS: Three hundred fourteen primary orbital malignancies were reported; 55% of malignant orbital tumors were lymphoma. The average annual incidence for all malignancies was 2 cases per million. There was a steady increase in the annual incidence of orbital malignancy during the 13 years of the study. Lymphoma showed the greatest rise in annual incidence. The average annual incidence of lymphoma increased 166% the last 6 years of the study compared to the first 6 years. CONCLUSIONS: A large increase in orbital lymphoma was documented in the Florida cancer registry from 1981 through 1993. The increase in incidence cannot be explained by improved compliance in reporting or by the small increase in incidence of systemic lymphoma during the survey period. Additional studies are needed to determine whether the observed increase in incidence in orbital lymphoma is genuine or spurious.

Spline regression in clinical research / La regresión por spline en la investigación clínica

OBJECTIVE: The objective of this article is to illustrate the statistical technique of spline regression, an under-utilized tool in clinical research. Spline regression was used to assess the dose-response association between serum albumin and hospital mortality. METHODS: Data from a previous study of patients hospitalized throughout Florida, United States of America (U.S.A.), for invasive group A streptococcal disease were accessed. For the current analysis, serum albumin (SA) at the time of admission was the risk factor of interest. The outcome was unadjusted hospital mortality among 117 patients. First, a traditional, suboptimal approach was employed by breaking SA into three groups and calculating the crude hospital mortality rate in each SA category. The second approach involved the creation of a curve using a quadratic spline model. RESULTS: The traditional approach yielded only three points of information: the hospital mortality rate for the three SA groups. Among patients whose SA upon admission was < 2.5 g/l00 mL, 2.5 to 3.4, and 3.5 or greater, the hospital mortality rate was 40.7, 14.8, and 8.3, respectively. The spline model, however, resulted in a smooth curve which was more clinically plausible. CONCLUSION: The goal of this paper is to expose clinicians to splines. Spline regression, unlike categorical analysis, does not impose the unrealistic assumption of a homogenous risk within categories. Another disadvantage of categorical analyses is that they allow large changes in risk between categories...