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M Sillero Arenas

Publications and source records attributed to M Sillero Arenas.

11 recordsLinked to original sources
PubMed1998

[The usefulness of intrinsic risk factors of infection of the surgical site as predictors of other infections and death].

BACKGROUND: The use of two indices of patient intrinsic risk of surgical site infection, the SENIC index and the NNIS index, have been recommended to adjust for the case-mix and improve the comparability of infection rates across different hospitals. We assess the usefulness of the indices in predicting other infection sites and in-hospital death. METHODS: A prospective study on 1,483 patients admitted to a service of general surgery was performed. The outcomes were nosocomial infection and in-hospital death. Relative risk and its 95% confidence interval were estimated. Unconditional logistic regression analysis was used to adjust for potential confounders. RESULTS: In the follow-up, 155 surgical site infections (10.5%), 19 postoperative pneumonias (1.3%), 33 urinary tract infections (2.2%) and 33 in-hospital deaths (2.2%). Both the NNIS index and the SENIC index showed a clear trend with infection risk and death; the higher the index, the higher the risk. After controlling for several confounders, the association was still observed. To assess whether the SENIC index added predictive power to the NNIS index (and vice versa) a linear regression analysis of the SENIC index on the NNIS index. A set of residuals (difference between the observed and expected values according to the regression equation) were estimated. In the logistic regression models, residuals of the NNIS index (part of the NNIS index unrelated to the SENIC index, whereas the residuals of the SENIC index did not increase the predictive power of the NNIS index. CONCLUSIONS: Both the SENIC index and the NNIS index are independent predictors of several sites of nosocomial infection and in-hospital death. The NNIS is a better predictor than the SENIC index.

Adult↗
PubMed1997

[Incidence of nosocomial infection surveillance in general surgery].

BACKGROUND: We have not found any study assessing the sensitivity of different frequencies of nosocomial infection surveillance (NIS). The objective of this study is to contribute to the ascertainment of the frequency of the NIS surveillance in surgical patients, where NIS has shown to be most efficient. METHODS: A prospective cohort study on 1,483 patients undergoing general surgery in a reference hospital was performed between November 1992 and July 1994. A daily NIS, plus review of clinical chart after hospital discharge, performed by two trained clinicians was taken as gold standard. The expected number of infections detected according to different schedules of NIS (from a minimum of weekly examination to a NIS performed every other day) was estimated taking into account the duration of infection and the hospital stay after infection healing. This number was corrected multiplying it by 0.9 (sensitivity of NIS without reviewing clinical chart after discharge). Confidence intervals (CI) were estimated using the binomial's exact method. RESULTS: 235 nosocomial infections were detected by the gold standard. The sensitivity of the weekly NIS for all infections was 78.3% (95% CI = 72.5-83.4); it varied from 63.6% (95% CI = 45.1-79.6) for urinary tract infections (UTI) to 85% (95% CI = 62.1-96.8) for respiratory tract infections; for surgical wound infections, it was 80.1% (95% CI = 72.4-86.5). As expected sensitivity increased with the frequency of NIS. A frequency of NIS every four days yielded a sensitivity for all infections of 86.4% (IC 95% = 81.3-90.5), 78.8% (CI 95% = 61.1-91.0) for UTI and 86.8% (CI 95% = 79.9-92.0) for SWI. CONCLUSIONS: Most nosocomial infections were detected by one visit a week. Twice visits a week improved the sensitivity of NIS in about 10%. It is important to emphasize that results change according to duration of infection and post-discharge hospital stay.

Cohort Studies↗
PubMedDate not supplied

[Prevalence of mental subnormality recorded in the province of Jaen].

It is done a cross-sectional study of the prevalence of mental retardation in the province of Jaén (Spain), based on the cumulated cases reported to the Institute of Social Services of the Social Security (INSERSO) until January 1, 1984. The main objective of this research is to know the prevalence of mental retardation in our province, and to analize its relationship with some sociodemographic variables. The prevalence obtained has been 4.09%, being a 59.27% of the prevalence due to endogenous/unexplained etiology. Mild subnormality constitutes a 8.4% of cases, being closely related with the size of the locality (municipio). Prevalence of mental subnormality showed a significative linear association with the size of the locality (r = -0.904, p less than 0.05), and with the population growth (r = -0.929, p less than 0.01). This relationship was not observed neither with the level of per capita income nor the altitude of the locality. A multiple regression analysis is made for every etiology of mental retardation and several social and geographic variables. We conclude that the figures for mental retardation in our province show a direct relationship with local development parameters.

Cross-Sectional Studies↗
PubMedDate not supplied

[Oral contraceptives and breast cancer: analysis of the statistical power of the association].

The power of the association between oral contraceptives and breast cancer was analysed in all the papers published up to date. Seventy-seven publications (from 44 studies) were collected and graded as to quality using meta-analytical methods. Power achieved a figure of greater than or equal to 0.8 in a 10.8% of the associations studied. It showed a significant relationship with the existence of a significant relative risk of the oral contraceptives for breast cancer. The relationship with the sample size of a study was not linear. Power did not show any significant relationship to other variables related to the design of a study (apart from matching, being the power higher in unmatched studies), or to the biases detected, although studies considered as unbiased yielded a higher power. Logistic regression analysis included as predictors of a power greater than or equal to 0.80 the existence of a significant relative risk and the lack of biases in a research.

Analysis of Variance↗
PubMedDate not supplied

[Meta-analysis in epidemiology (1): the general characteristics].

In the present work the general characteristics, aims and applications of meta-analysis in public health are described. The general rules and the relevant steps for the development of this type of studies are considered. These points are illustrated with a number of real examples and the advantages and limitations of the different methodological options are commented.

Epidemiologic Methods↗
PubMedDate not supplied

[Meta-analysis in epidemiology (2): quantitative methods].

The main goal of this paper is to offer an introduction to the quantitative methods of meta-analysis used in epidemiology/public health, emphasizing on the most widespread used. We give also a brief reference of the methods to recognize publication bias. The limitations and advantages of the methods commented on are discussed.

Bias↗
PubMedDate not supplied

[Proportional mortality studies: criteria for the selection of participant groups].

Proportional mortality designs are used widespread in occupational epidemiology. In this review those biases which can affect them, mainly the healthy worker bias, are discussed. Several options for their analysis and the assumptions to be accomplished for validity are reviewed: proportionate mortality analysis, standardized mortality ratio, and odds ratio. The inclusion of dead participants in a research exhibits several drawbacks. Starting out from the analysis of this sort of designs, the first criterium to select diseases is similar to case-control studies: the reference group must not include diseases related with the exposure under study. Analyzing the relationship between mortality and incidence rates, criteria to select diseases to be investigated by proportional mortality studies are offered. These designs yield a valid inference when the disease is rare and irreversible. If the exposure shortens duration of disease, a toward-the-null bias is introduced. The direction of bias is variable under other circumstances, although it shows a trend to be negative.

Epidemiologic Methods↗
PubMedDate not supplied

[Inclusion of research quality in meta-analyses].

The objective of this review is how study quality is taken into account in the synthesis of information from several studies. Meta-analysis has been criticized for failing into account differential quality of evidence in primary studies, allowing poor studies to drive out good science by weight of numbers. Notwithstanding there is presently no agreement on the inclusion of study quality score in quantitative meta-analysis; on the other hand, agreement does exist on knowing study quality. However, and although there is a certain level of consensus about what a good study is and on what characteristics it should have, no evaluation protocol on study quality is uniformly accepted. Furthermore, there are no data on the reliability and validity of quality questionnaires. There are several procedures to include study quality in meta-analysis: a) it is generally accepted that bias-free studies should be pooled only; b) most researches reject to include quality scores in the weight; and c) no agreement is reached on the use the quality scores as a covariate in graphical methods and regression analysis. It may be superfluous or misleading.

Meta-Analysis as Topic↗
PubMedDate not supplied

[Oral contraceptives and cancer of the cervix uteri. Analysis of the strength of the association].

The power of the association between oral contraceptives and cervical cancer was analysed in all the papers published up to date. Fifty-three publications (from 48 studies) wer collected and graded as to quality using meta-analytical methods. Power achieved a figure of greater than or equal to 0.8 in a 24% of the associations studied. It showed a significant relationship with the existence of a significant relative risk of the oral contraceptives for cervical cancer, with the quotient between sample sizes of reference and index groups, and with the sample size of a study, although the relationship was not linear to these two latter variables. Power did not show any significant relationship to other variables related to the design of a study, or to the biases detected. Logistic regression analysis included as predictors of a power greater than or equal to 0,80 the existence of a significant relative risk and the use of adjusted relative risk.

Carcinoma↗