[Tuberculosis in the Zaragoza province. Estimation by means of the capture-recapture method]. / La tuberculosis en la provincia de Zaragoza. Estimación mediante el método captura-recaptura.

INTRODUCTION: Tuberculosis (TB) is an underreported condition to the Communicable Diseases Control System (CDCS). The objective of this work was to estimate the actual incidence of tuberculosis and the epidemiological characteristics of the diseases in the Zaragoza province. MATERIAL AND METHODS: Retrospective study in which the capture-recapture method was used to estimate the number of tuberculosis cases, by using the microbiology laboratories and the CDSC as data sources. The socio-demographic and clinical characteristics of diagnosed patients throughout three years in this province were analyzed. RESULTS: The mean annual incidence rate of TB was 22.02 per 100,000 inhabitants according to microbiological data, and 48.5 per 100,000 according to the capture-recapture method. A total of 569 patients were studied, and 400 of them were males (70.3%). The mean age was 43.2 years, and the 25-34 year-old group had the highest number of cases (27.9%). Twenty-three percent of cases were co-infected with HIV, and 77.4% were parenteral drug abusers, and 4.4% immigrants. CONCLUSIONS: The capture-recapture method has demonstrated to be useful to know the relevance of TB in our setting. The actual incidence of tuberculosis was higher than that pointed out by the CDCS. Relevant differences were observed regarding incidence rates by age and sex groups. HIV infection and immigration do not appear to explain the frequency of this disease in our setting.

Evaluation of two retrospective active surveillance methods for the detection of nosocomial infection in surgical patients.

OBJECTIVE: To compare the sensitivity and specificity of two retrospective active surveillance methods based on review of the medical record and review of the discharge form in identfying nosocomial infection, taking the prospective surveillance method as the reference standard. DESIGN: Blind comparison of three active nosocomial infection surveillance methods. SETTING: Department of General Surgery of a tertiary-care hospital with a referral population of 266,000 people. METHODS: All operated patients admitted to the Department of Surgery for more than 24 hours and discharged from January 1, 1994, to December 31, 1994, were included. Prospective surveillance consisted of daily review of the patient's record during hospitalization. Retrospective surveillance consisted of review of the medical record and the discharge form. Sensitivity and specificity of both retrospective methods were calculated. RESULTS: Of the 1,514 patients included in the study, 1,476 (97.5%) were reviewed by means of the retrospective surveillance system. A total of 20, 8, and 4 hours per week was needed for the active prospective system, review of the medical record, and review of the hospital discharge form, respectively. The documented cumulative incidence of nosocomial infection was 21.8% for the prospective system, 19.6% for review of the medical record, and 12.6% for review of the discharge form. The overall sensitivity of review of the medical record was 88% and of the discharge form 56%, with a specificity of 99%. For review of the medical record, the highest sensitivity was 93%, for urinary tract infections; for review of the discharge form, the highest was 57%, for surgical-wound infection. CONCLUSIONS: The retrospective method of review of the medical record was the most efficient active surveillance strategy in detecting nosocomial infection in surgical patients.

The association between vasectomy and prostate cancer: a systematic review of the literature.

OBJECTIVE: To evaluate the possible association between vasectomy and prostate cancer. DESIGN: Systematic review of the literature. PATIENT(S): Fourteen original studies published between January 1985 and December 1996 that addressed the association between vasectomy and prostate cancer. MAIN OUTCOME MEASURE(S): The strength of the association was estimated with the use of a meta-analysis (DerSimonian and Laird method). A sensitivity analysis was conducted to assess the impact of different sources of heterogeneity. RESULT(S): Fourteen original papers were reviewed (5 cohort and 9 case-control studies). Relative risks ranged between 0.44 (95% confidence interval [CI] = 0.1-4.0) and 6.70 (95% CI = 2.1-21.6). The overall relative risk (DerSimonian and Laird estimate) was 1.23 (95% CI = 1.01-1.49). The sensitivity analysis showed that this measure was very sensitive to the study base, the type of design used, and the possibility of bias. Further, the funnel plot demonstrated the probable existence of publication bias. CONCLUSION(S): No causal association was found between vasectomy and prostate cancer. Individuals who have undergone vasectomy are not at high risk for the development of prostate cancer.

PIP: The absence of a plausible biologic model, methodologic problems, and lack of consistency between the results of different studies have created skepticism about any association between vasectomy and prostate cancer. To clarify further the possibility of such a link, a systematic review of the empirical literature published in 1988-96 was conducted. 14 such studies (5 cohort and 9 case-control) were identified, 11 of which found an excess risk of prostate cancer in men who had undergone vasectomy. Relative risks ranged from 0.44 (95% confidence interval (CI), 0.1-4.0) and 6.70 (95% CI, 2.1-21.6). The risk was statistically significant in 6 studies. The weighted relative risk obtained using the age-adjusted results of the individual studies was 1.23 (95% CI, 1.01-1.49). However, both the statistical tests and the qualitative analysis detected heterogeneity between the studies. Possible sources of this heterogeneity include type of design, study base, presence of detection bias, and inadequate selection of controls. Moreover, the sensitivity analysis indicated that the detected effect depends to a great extent on studies that are more vulnerable to bias (i.e., case-control and hospital-based studies) and those that have internal validity problems. Further, the funnel plot demonstrated the possible existence of publication bias. Finally, when the relative risk was recalculated to exclude early stage tumors (located by active detection in vasectomy cases), the previously found association between vasectomy and prostate cancer disappeared. It is concluded that the available empiric evidence is of low quality because of multiple sources of bias that favor the overestimation of the effect of vasectomy on prostate cancer risk. These validity problems, along with the lack of a biologic model to explain the association, strongly suggest the association is not causal.

[Nosocomial infections in surgical patients. Problems of measuring and comparing results]. / Infección nosocomial en pacientes quirúrgicos. Problemas de medición y de comparación de resultados.

BACKGROUND: What is striking when studying the frequency of nosocomial infection (NI) is the variability of the study data. Different frequency indicators and infection criteria are used for estimates and these make it difficult to compare works. The aim of this work is to estimate the frequency of hospital infection by using different indicators to compare the results. METHODS: A market study was carried out including patients admitted to four surgical units over the period of one year. The following indicators were used: proportion of patients infected, cumulative number of cases of infection and density of number of cases. The infections were detected through active search and included those acquired in Intensive Care Units and those diagnosed after patients had been discharged from hospital. RESULTS: A total of 14.5% of the patients suffered NI and 5% of the infections were diagnosed after discharge from hospital. In 38.5% of the cases of infection a microbiological study was not requested. The General Surgery Unit had the highest figures for the three indicators. Nevertheless, the magnitude of the differences between services was modified in line with the indicator used. CONCLUSIONS: The real percentage of patients with NI is higher than the values given by the usual monitoring systems. Given the trend witnessed over recent years whereby the length of hospital stays is being reduced and early discharge programmes promoted with the aim of increasing efficiency, densities for the number of cases should be estimated and these should include the NI cases diagnosed after hospital discharge in order to make valid comparisons between different institutions and periods of time.

[The incidence and distribution of accidents with biological fluids among health personnel and the general population]. / Incidencia y distribución de accidentes con fluidos biológicos en personal sanitario y población general.

OBJECTIVES: To assess the informative usefulness of the Registry, to calculate the incidence rates of accident with biological fluids among health care workers and in the community, to know about the postaccident rate of seroconversion to HIV and to identify risk groups. METHODS: A descriptive study of the HIV records file of the Registry of Accidental Contacts to Biological Fluids in the Clinic Hospital of Zaragoza was conducted, between January 1987 and September 1993. The registry includes the reports of health care workers and the general population of Health Area III in Aragón (Spain), except for the Calatayud's Hospital. Incidence rates, rate ratios and their 95% confidence intervals were calculated. RESULTS: A total number of 595 accidents were reported, in none of them and HIV infection occurred subsequently. The incidence rate in health care workers was of 1.7 reports per 100 workers per year, while in the community it was of 8.1 per 100,000 people. The housekeeping staff was the group with a higher incidence (rate = 6.7; 95% IC: 3-14.8) and the type of accident more frequently described was needlestick injury. CONCLUSIONS: The incidence of reported accidents has increased in the community and in health care workers, which may be due to the increase in the reporting. In health care workers, the incidence in 1993 was within the range reported from other countries. The perception of risk is universal after accidents with unknown biological fluids. The correct disposal of material with biological contamination should be the more important preventive action.

[Survival in cancer of the breast in Zaragoza (1960-1990) in relation to age, clinical stage and period of time of the diagnosis]. / Supervivencia del cáncer de mama en Zaragoza (1960-1990) en relación con la edad, estadio clínico y período de tiempo del diagnóstico.

BACKGROUND: The characteristics of a population based series of 3,066 women diagnosed with breast cancer collected by the Cancer Registry of Zaragoza, Spain from 1960 to 1990 are herein described. Gross short and long term survival, as well as specific survival were estimated according to age at diagnosis, tumor stage and the period in which the patient was diagnosed. METHODS: Every patient was followed up to verification of death or to the latest information available up to January 1, 1991. Diagnosis specified in writing in the clinical history and support by surgical or anatomopathologic reports were required. The data concerning place and site of residence and the vital status of the cases were verified by the municipal and civil registries, death certificates and burial registries. The survival curves were estimated by the Kaplan-Meier method, and short and long term survival, by age and tumor stage at diagnosis and the diagnostic period were also evaluated. RESULTS: Gross survival was estimated as 89.1% in the first year, 50.9% at 5 years, and 34.7%, 28.4% and 20.0% at 10, 15, 20 and 25 years, respectively. Survival at 5 years according to TNM clinical stage classification (UICC-AJC 1978) was 90% for stage I, 69.5% for stage II, 44.6% for stage III and 20.6% for stage IV. The cases diagnosed between 1980 and 1990 presented better survival than those previously diagnosed. The differences were statistically significant in all the cases (p < 0.001, log-rank test). CONCLUSIONS: A slight improvement has been observed in the survival of women diagnosed with breast cancer in Zaragoza, Spain during the study period. Despite of that fact, the survival rates were worse than those observed in other countries with similar socioeconomic development.

[Annual incidence and control of nosocomial infections in a county hospital]. / Incidencia anual y control de las infecciones intrahospitalarias en un hospital comarcal.

BACKGROUND: The recommendation of Centers for Disease Control that hospitals must have a person trained in infection control per 250 beds has been understood as a law of all or nothing hindering implementation of hospital infection surveillance and control programs in small hospitals. Since the importance that small regional hospitals have in the Spanish Health System, the aim of this study is to describe the magnitude and characteristics of nosocomial infections (NI) in a small regional hospital in case this position needs being reconsidered. METHODS: The study was carried in Hospital de Calatayud, a small regional hospital of 122 beds belonging to Health Area III of Aragon. All the NI that occurred during 1992 were recorded by means of an uninterrupted system of prospective surveillance based on a multirecord revision. Both of the Accumulate Incidence of NI (AINI) and Accumulate Incidence of Patients with one or more NI (AINP) were calculated and the main variables associated with NI were described. RESULTS: Altogether, 298 NI were detected in 242 patients during that year. The AINI was 7.1% and the AINP was 5.8% with a mean of 1.2 (SD = 0.6) HI per infected patient. The most frequent types of NI were urinary tract infection, surgical wound infection and lower respiratory tract infection. Some pathogen microorganism were identified in 43% of NI. The microorganisms most frequently associated with NI were Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus. Mortality associated with NI was 11% and the average stay of patients with some NI was 22.9 days (SD = 22.1). CONCLUSIONS: Results point out the need for implementing hospital infections surveillance and control programs in small hospitals too.

[Mortality from cancer of the breast and the female genitalia in Aragón, 1975-1984]. / Mortalidad por cáncer de mama y del aparato genital femenino en Aragón, 1975-1984.

One out of four cancer deaths in women are due to breast cancer and female genital cancer. Mortality data are a basic information source to study disease characteristics in the population. A descriptive study on breast and female genital cancer mortality was carried out in Aragón covering the period 1975-84. Geographical differences and variations on mortality rates between the periods 1980-84 and 1975-79 have been studied. A mortality rate of 40.2 per 100,000 women per year has been observed for these tumours. Breast cancer accounted for 55% of these deaths. Reduction of mortality rate was seen for uterus non-specified between the periods 1980-84 and 1975-79, probably due to an improvement in quality of death certificates for uterus cancer. Higher mortality rates have been observed in the town of Zaragoza than in other parts of Aragón. This suggests the town of Zaragoza as priority in strategies of prevention and control programs.

[Incidence of cancer of the breast and the female genital system in the province of Zaragoza, 1975-1984]. / Incidencia del cáncer de mama y del aparato genital femenino en la provincia de Zaragoza, 1975-1984.

BACKGROUND: Cancer of the breast and female genital organs represents 40% of the tumors found in women. Registers of cancer on a population base constitutes a basic source of information for measuring the incidence of these tumors in the population. METHODS: The magnitude of cancer of the breast and female genital organs was analyzed in the province of Zaragoza during the period 1975-1984 according to the different geographic areas in the province. The rate of incidence, accumulated incidence and the rate of incidence adjusted by age were calculated. The source of information used was the Register of Cancer of Zaragoza. RESULTS: The rate of incidence observed for these tumors was found to be 84 per 100,000 women/year with breast cancer representing 58% of the cases. The truncated rates were higher than the rates of incidence except for the localization of other genital organs indicating a greater frequency of these tumors at intermediate ages. In Zaragoza, the capital city, an excess of incidence was found for most of the localizations studied. This may be explained by the existence of greater frequency of these tumors in urban areas. In the capital this excess was not observed for unspecified cancer of the uterus. This may be due to the greater precision of diagnosis in the capital than in the rest of the province because of the availability of health care centers. CONCLUSIONS: In the province of Zaragoza, cancer of the breast is most frequent than cancer of any of the other female genital organs. The greatest frequency of these neoplasms was found at an intermediate age. In Zaragoza city, a greater frequency of cancer was registered than in the rest of the province. These results are of interest for the proposal of programs for prevention and control.