Biomedical subjects

M Delgado-Rodríguez

Publications and source records attributed to M Delgado-Rodríguez.

At least 37 records · Page 2Linked to original sources

PubMed2000

Competing risks in absence of independence: impact of AIDS on liver function failure mortality, and lung cancer on ischemic heart disease mortality.

The increase in lung cancer (LC) mortality can produce a decrease in mortality from other causes, including ischemic heart disease (IHD). This problem (called the competing risks problem) has been addressed usually assuming independence between the competing causes of death. Our purpose is to show that assuming dependence of causes of death allows obtaining a better estimation of cumulative mortality. We use a clinical epidemiological example on the impact of AIDS in liver function failure in a cohort of drug users. The competing effect under dependence is 47% higher than under independence. This result is compared with a population-based example on LC and IHD mortalities in Spanish people in 1992. LC and IHD share tobacco smoking as a common risk factor, so independence cannot be assumed. Under the independence assumption, both life expectancy and number of deaths from IHD are underestimated. The difference is small compared to the model computed under dependence and it occurs mainly in the elderly (0.3% more deaths in people aged 70 and over).

Acquired Immunodeficiency Syndrome↗

PubMed2000

Analysis of risk factors for nosocomial sepsis in surgical patients.

BACKGROUND: This study aimed to identify patients at high risk for developing sepsis following surgery according to criteria determined by the American College of Chest Physicians and the Society of Critical Care Medicine Consensus Conference on sepsis. METHODS: A prospective case-control study was performed in surgical patients in a tertiary care centre over 1 year. Patients were identified by a daily prospective surveillance. Controls were selected randomly from the daily list of surgical inpatients. Data were collected prospectively. Crude and adjusted odds ratios (ORs) and their 95 per cent confidence intervals were computed using logistic regression analysis. RESULTS: During follow-up, 99 cases and 99 controls were identified. The main risk factors for sepsis found in the multivariate analysis were coma within 48 h before sepsis (OR 13.5, 95 per cent confidence interval 3.6-50.8), low serum albumin level at admission (OR 15.8, 5.4-46.4), two or more intrinsic co-morbidities (OR 11.8, 2.8-49.4) and parenteral nutrition (OR 5.1, 1.5-17.1). Emergency surgery (OR 3.0, 1.4-6.4), abdominal surgery (OR 2.6, 1.0-6.8) and number of surgical interventions (OR 2.5, 1. 1-6.1) were the variables related to surgery that significantly increased the risk of sepsis. Both the study on the Efficacy of Nosocomial Infection Control (SENIC) and the National Nosocomial Infections Surveillance indices showed a statistically significant trend with sepsis. CONCLUSION: Patient-related factors appear to represent the greatest risk for developing postoperative nosocomial sepsis, rather than factors associated with the surgery.

Case-Control Studies↗

PubMed2000

Applicability of two surgical-site infection risk indices to risk of sepsis in surgical patients.

OBJECTIVE: To compare the ability of the Study of the Efficacy of Nosocomial Infection Control (SENIC) and the National Nosocomial Infection Surveillance (NNIS) indices to predict the development of nosocomial sepsis in subjects undergoing surgery. DESIGN: 1-year prospective case-control study. SETTING: A tertiary-care center in Spain. PATIENTS: Cases were surgical patients with nosocomial sepsis defined using the criteria of the Consensus Conference on Sepsis, identified by daily prospective surveillance. METHODS: Controls were randomly selected from the daily list of surgical inpatients. Data were prospectively collected. To determine whether either index added explanatory information to the other, two methods were used. The first method involved computing a set of residuals for both variables. Residuals and primary variables were introduced in logistic regression models. The second method evaluated both indices with the Goodman-Kruskal (G) nonparametric coefficient. RESULTS: 99 cases and 97 controls were included. After controlling for confounders, both the SENIC index (P<.001) and the NNIS index (P=.04) showed a significant trend. Residuals of the SENIC index added discriminating ability to the NNIS index, whereas residuals of the NNIS index did not improve the prediction ability of the SENIC index. Similar results were yielded by the G statistic: the SENIC index showed higher predictive power than the NNIS index (G=0.56 vs G=0.41). CONCLUSIONS: Both indices performed about equally well for discriminating risk of nosocomial sepsis. The SENIC index had a somewhat better ability than the NNIS index only when the number of discharge diagnoses (not truly a predictive factor) were involved in the calculation of the SENIC index.

Case-Control Studies↗

PubMed2000

Epidemiological differences between sepsis syndrome with bacteremia and culture-negative sepsis.

OBJECTIVE: To explore the association of putative disease markers and potential risk factors with the nosocomial sepsis syndrome. DESIGN: Prospective case-control study matched for gender, age, and length of preinfection hospital stay. SETTING: 1,200-bed tertiary-care center in Spain. PATIENTS: Cases were selected using the sepsis syndrome criteria of the American College of Chest Physicians/Society of Critical Care Medicine Consensus Conference and were divided into three groups: sepsis with bacteremia (109 cases), sepsis with positive culture other than blood (122 cases), and sepsis with negative culture (115 cases without documented infection but with sepsis syndrome, clinically suspected infection, and empirical antibiotic treatment). Controls were randomly selected from the daily list of inpatients. Data were collected prospectively. Crude and multiple-risk-factor-adjusted odds ratios and their 95% confidence intervals were computed using conditional logistic regression analysis. RESULTS: Presence of coma in the 48 hours before sepsis, intensive care unit (ICU) stay, and decreased serum albumin levels at admission were common epidemiological markers identified for the three groups of cases. Having a central venous catheter was the main healthcare-related risk factor for bacteremia. ICU stay and nasogastric tube were the main risk factors for sepsis with positive culture other than blood. Coma within 48 hours before sepsis and the need of intensive care were the only two markers identified for culture-negative sepsis. CONCLUSION: Culture-negative sepsis does not behave like culture-positive sepsis, and this may imply that implementation of preventive measures to decrease the risk of bacteremia may not decrease the risk of sepsis syndrome.

Bacteremia↗

PubMed2000

Comparison of the performance of two general and three specific scoring systems for meningococcal septic shock in children.

OBJECTIVE: To evaluate the performance at admission to the pediatric intensive care unit (PICU) of five severity scores, two general (the Pediatric Risk of Mortality [PRISM] II and III scores) and three specific for meningococcal septic shock (Leclerc, Glasgow Meningococcal Septicemia Prognostic Score [GMSPS], and Gedde-Dahl's MOC score) in children with this condition. DESIGN: Multicenter, retrospective, cohort study. SETTING: The PICUs from four tertiary centers. PATIENTS: Patients were 192 children ranging in age from 1 month to 14 yrs consecutively admitted to the participating PICUs during a period of 12 yrs and 6 months (January 1983 to June 1995), who were diagnosed with presumed or confirmed meningococcal septic shock. Patients with a length of stay <2 hrs were excluded from the study. INTERVENTIONS: Clinical and laboratory data gathered during the first 2 hrs after admission were used to compute the scoring systems tested. MEASUREMENTS AND MAIN RESULTS: There were 66 deaths (34%). Neisseria meningitidis was cultured from 142 (74%) children. GMSPS and PRISM II provided the best discriminative capability, as measured by the area under the receiver operating characteristic curve (SEM): 0.816 (0.036) and 0.803 (0.041), respectively. The other three scores gave lower receiver operating characteristic areas: PRISM III = 0.777 (0.043), MOC = 0.775 (0.037), and Leclerc = 0.661 (0.045). There was a statistically significant difference between the areas under the receiver operating characteristic curve of GMSPS and Leclerc (p < .01) but not between the GMSPS and the remaining three scores. All five scores presented good calibration with no significant differences between observed and predicted mortality (Hosmer-Lemeshow goodness-of-fit test). CONCLUSIONS: The specific GMSPS and the general pediatric severity system PRISM II performed better than the other three scores, being appropriate tools to assess severity of illness at admission to the PICU in children with presumed meningococcal septic shock.

Adolescent↗

PubMed1999

Polymorphisms in the presenilin 1 and presenilin 2 genes and risk for sporadic Alzheimer's disease.

We examined the possible involvement of polymorphisms of the presenilin 1 (PS1) and presenilin 2 (PS2) genes in the risk for sporadic Alzheimer's disease (AD), either through an independent effect or through interaction with the existing apolipoprotein E (ApoE) risk, in 211 AD cases and 188 age-matched control subjects. No significant differences were obtained in any of the comparisons relating the effect of the PS1 and PS2 polymorphisms; thus, these polymorphisms do not appear to be sufficient risk factors by themselves for sporadic AD. Although the ApoE varepsilon4 genotype is the only definite predictor of risk, homozygosity for either the 1 allele of the PS1 or the C allele of the PS2 genes may increase the risk conferred by the presence of an ApoE epsilon4 allele. Additionally, combination of PS1/11 and PS2/CC genotypes might have a small synergistic effect on the risk for AD.

Adult↗

PubMed1999

Nosocomial infection, indices of intrinsic infection risk, and in-hospital mortality in general surgery.

The objectives of this paper are to assess whether two indices of intrinsic infection risk (the SENIC and the NNIS index) predict in-hospital mortality and the attributable in-hospital mortality due to nosocomial infection in surgical patients. A prospective study on 4714 patients admitted to three hospitals has been carried out. The relative risk and its 95% confidence interval (CI) were estimated. Multiple-risk factors adjusted for odds ratios (OR) were yielded by logistic regression analysis. Overall, 119 patients (2.5%) died before hospital discharge. Both the SENIC and the NNIS indices were related to in-hospital mortality in crude data. After controlling for several variables (age, sex, ASA score, cancer, renal failure, diabetes mellitus, stay at the ICU), the SENIC index did not show any significant trend with mortality (P = 0.252), whereas the trend was significant for the NNIS index (P < 0.001). Risk of death in patients with one nosocomial infection was 7.5%, and in patients developing more than one nosocomial infection was 17.1%. After adjusting for several confounding variables, the development of an organ/space surgical site infection was significantly related to mortality (OR = 4.5, 95% CI 1.5-15.6) as was blood infection (OR = 17.3, 95% CI 3.5-87.0). The association of a surgical site infection and either a respiratory tract infection or a blood infection also increased significantly the risk of in-hospital mortality (OR = 3.3, 95% CI 1.2-8.7). In conclusion, the NNIS index is a good predictor of in-hospital mortality. Patients developing an organ/space surgical site infection and/or a blood infection have an increased risk of in-hospital mortality.

Adult↗

PubMed1999

Risk factors for monoinfections and coinfections with HIV, hepatitis B and hepatitis C viruses in northern Spanish prisoners.

A cross-sectional study was conducted in prisons of Cantabria (northern Spain) from June 1992 to December 1994. Inmates were asked to participate in a survey on prevalence and risk factors for monoinfections and coinfections with HIV, HBV and HCV. Crude and multiple odds ratios of risk factors were calculated (by polychotomous logistic regression). Prevalence of coinfections was higher than that of monoinfections. IDU risk factors were the main independent variables associated with monoinfections and coinfections with these agents. The strength of association increased with the degree of coinfection for IDU risk factors and penal status, e.g. duration of injecting drug use for more than 5 years yielded an adjusted OR ranging from 1.3 (95% CI: 0.4-5.1) for HBV monoinfection to 180 (95% CI: 61.0-540.0) for HIV-HBV-HCV coinfection. In comparison, sexual behaviours were less important than IDU risk factors.

Adult↗

PubMed1999

Coinfections by HIV, hepatitis B and hepatitis C in imprisoned injecting drug users.

In order to know the prevalence and risk factors for coinfections by human immunodeficiency virus (HIV), hepatitis B virus (HBV) and hepatitis C virus (HCV) among injecting drug users (IDUs), a cross-sectional study was carried out in two prisons of the province of Cantabria, northern Spain. Three hundred and sixty-two IDU inmates were recruited. All inmates were interviewed and their blood tested for HIV, HBV and HCV. Crude and multiple risk factor adjusted for (by polychotomous logistic regression) odds ratios were calculated. Prevalence of HBV-HCV coinfection (42.5%) was higher than HIV-HBV-HCV coinfection (37.3%), whereas monoinfections were very uncommon (overall: 13%). Long-term injectors and reincarceration were the foremost risk factors for both coinfections, showing a trend between the degree of association and the number of viruses infecting a patient. No significant relationship between coinfection status and sexual practices was observed. The results related to coinfections are consistent with previous studies of prevalence and risk factors for HIV, HBV and HCV, in indicating that the high rates of coinfections among IDU inmates emphasise the need to harm-reduction policy across prisons in Spain.

Adult↗

PubMed1999

The naevus count on the arms as a predictor of the number of melanocytic naevi on the whole body.

A study of melanocytic naevi was carried out in southern Spain to examine the relationship between numbers of naevi at different body sites as predictors of whole-body naevus count and to determine whether the naevus count on the arms is valid for identifying the risk factors for total naevi. Subjects were the control group from a case-control study on risk factors for cutaneous melanoma. They were selected from visitors to the University of Granada Hospital (southern Spain) between 1989 and 1993. Of 200 people invited to participate, 146 accepted (73%). Data were collected by personal interview, and melanocytic naevi were counted over the entire body surface by clinical skin examination performed by one dermatologist. Partial correlation coefficients (R) estimated by multiple linear regression were calculated. Comparisons between whole-body naevi and naevi on the arms, and their relationship with risk factors, were assessed by analysis of variance and covariance. Arms in men (adjusted R = 0.88) and thighs in women (adjusted R = 0.82) were the best predictors of total naevi after adjusting for age and sun exposure. Age, occupational and leisure sun exposure, and sunburns showed significant correlations with the total number of naevi. Similar results were found for the naevus count on the arms. In conclusion, the prediction of whole-body numbers of naevi by a naevus count on specific sites differs between men and women: arms in men and thighs in women are the best predictors. Nevertheless, naevus counts on the arms allowed us to study the risk factors for total naevi as well as whole-body naevus count: age and occupational sun exposure were the strongest determinants.

Adult↗

PubMed1999

The effect of frequency of chart review on the sensitivity of nosocomial infection surveillance in general surgery.

OBJECTIVE: To assess the sensitivity of different frequencies of nosocomial infection surveillance (NIS) in general surgery. DESIGN: Data obtained with a prospective daily NIS are compared with those of hypothetical cross-sectional studies carried out with different frequencies (from one weekly visit up to one visit every other day). SETTING: General surgery services at three hospitals. MAIN OUTCOME MEASURE: Sensitivity in the detection of nosocomial infection (overall and stratified by site), compared to a gold standard of prospective surveillance of every patient's complete medical record daily from the first day after surgery until discharge and once more after discharge. PATIENTS: 5,859 patients. RESULTS: 837 nosocomial infections were detected by the gold standard (58.8% were surgical-site infections [SSI]). The sensitivity of weekly NIS for all infections was 74.5% (95% confidence interval [CI95], 71.4%-77.5%) and varied from 65.1% (CI95, 56.2%-73.3%) for urinary tract infection to 83.3% (CI95, 62.6%-95.3%) for respiratory tract infection; it was 76.4% (CI95, 72.4%-80.1%) for SSI. As expected, sensitivity increased with the frequency of NIS. Performing NIS every 4 days improved sensitivity significantly, to 82.3% (CI95, 79.5%-84.8%) for all infections and 83.3% (CI95, 79.7%-86.5%) for SSI. One visit every other day increased the sensitivity for all infections by another 4.9%, mainly due to increased detection of urinary tract and other less severe infections. CONCLUSIONS: The sensitivity of two visits a week exceeded that of one weekly visit by approximately 8%, and one visit every other day added another 5% increase. Results varied according to duration of infection and postdischarge hospital stay.

Bacterial Infections↗

PubMed1999

Increase in cervical cancer mortality in Spain, 1951-1991.

BACKGROUND: The trend in cervical cancer mortality in Spain from 1951 to 1991 is examined. METHODS: Analysis of national mortality statistics calculating age standardised mortality rates and an age-period cohort analysis. A fit to the Gompertz function was made to estimate the influence of the environmental factors on the mortality rates evolution. MAIN RESULTS: The age standardised mortality rate in Spain is lower than in other developed countries (USA or Estonia) and equal to Norwegian and Finland rates; but whereas in these countries the trend is to decrease, the Spanish rate has increased during this period, because of a cohort effect. A misclassification bias could be responsible for the trend in women aged 40 and older but the increasing trend in younger women could not be interpreted as espurious. The Gompertzian analysis suggests an increase in environmental factors causing cervical cancer. CONCLUSIONS: Cervical cancer mortality rates are increasing in Spain because of environmental factors.

Adult↗

PubMed1999

[Biases in meta-analysis].

The objective of the present article is to review the biases in meta-analysis. This procedure can be included within observational studies, and its biases follow the same classification: selection, information and confounding bias. Selection bias can always be present because of the impossibility of enumerating the reference population. More interest deserves publication bias, influenced by many facts: significant results, design type, language of publication, the existence of conflicts of interest, sample size, institutional prestige, existence of prejudices, and regression to the mean. There are several graphic and quantitative procedures to detect the error under certain assumptions. The correction of this bias is quite unlikely. It is easier to guarantee that the selection process of the studies among those located is not subjected to errors, if structured protocols are used. Information bias has been less studied, but it has also been documented. Control of confounding bias depends on the identification of this error in the individual studies, but it can also be introduced through certain analytic techniques, as the ecologic fallacy. Lastly, it is recommended not to use the procedure of Peto in the analysis as this technique provides biased results.

Conflict of Interest↗

PubMed1999

[Biases in the study of prognostic factors].

The main objective is to detail the main biases in the study of prognostic factors. Confounding bias is illustrated with social class, a prognostic factor still discussed. Within selection bias several cases are commented: response bias, specially frequent when the patients of a clinical trial are used; the shortcomings in the formation of an inception cohort; the fallacy of Neyman (bias due to the duration of disease) when the study begins with a cross-sectional study; the selection bias in the treatment of survivors for the different treatment opportunity of those living longer; the bias due to the inclusion of heterogeneous diagnostic groups; and the selection bias due to differential information losses and the use of statistical multivariate procedures. Within the biases during follow-up, an empiric rule to value the impact of the number of losses is given. In information bias the Will Rogers' phenomenon and the usefulness of clinical databases are discussed. Lastly, a recommendation against the use of cutoff points yielded by bivariate analyses to select the variable to be included in multivariate analysis is given.

Bias↗

PubMed1998

Risk factors for low birth weight: results from a case-control study in southern Spain.

The main objective of this study is to examine the effect of several variables, including altitude of maternal residence, on delivering a low birth weight (LBW) newborn. A case-control study was done. Two hundred forty cases (single newborn weighing less than 2,500 g) and 374 controls (single newborn weighing more than 2,499 g) were included. Information was gathered from the clinical chart of delivering women, through a personal interview and the Spanish Census Bureau (for altitude). Predictors of LBW were assessed through stepwise logistic regression analysis. Several well-known LBW risk factors were identified: hypertension, weight gain during pregnancy, body size (mainly maternal prepregnancy weight), low social class, primiparity, and several conditions (spontaneous delivery, abruptio placentae). Altitude was an independent predictor of LBW at term (more than 37 weeks of gestational age) but not for preterm LBW. Nevertheless, a relationship between altitude and birth weight was not found in controls, although a moderate decreasing gradient with altitude was observed. The limitations of these findings are discussed.

Adult↗

PubMed1998

Risk factors for surgical site infections diagnosed after hospital discharge.

A prospective cohort study on 1103 consecutive patients undergoing general surgery with a follow-up of up to 30 days was undertaken to analyse the risk factors for surgical-site infection (SSI). Relative risks (RRs), crude and multiple-risk factors adjusted for by logistic regression analysis, and their 95% confidence intervals were calculated. One hundred and four patients (9.4%) developed infection, 81 in hospital and 23 at home. Predictors for in-hospital SSI differed from those for post-discharge SSI. In a crude analysis, an increased risk of post-discharge SSI occurred after clean-contaminated surgery (but not contaminated surgery). Stepwise logistic regression failed to identify any significant predictor for post-discharge SSI.

Adult↗

PubMed1998

[Gompertzian analysis of ischemic cardiopathy mortality in Spain, 1951-1992].

INTRODUCTION AND OBJECTIVES: In Spain ischemic heart disease mortality was increasing prior to 1975 and has decreased since 1975. This trend is common to both genders. The goal of this paper is to separate the genetic, environmental and competitive risk factors influencing this evolution. METHODS: The Gompertz function was adjusted cross-sectionally to age-specific mortality due to ischemic heart disease for each year from 1951 to 1992. The Gompertzian longitudinal analysis was applied to the coefficients obtained to estimate the effect due to environmental and competitive factors. RESULTS: Ischemic heart disease in Spain is a Gompertzian disease with an intersection point at 67 years for men and 40 years for women. Environmental factors were increasing before 1975 and have decreased since then. However, the competitive factors decreased in men since 1980 and in women since 1951 on. CONCLUSION: The evolution of risk factors (smoking, hypercholesterolemia and hypertension) is responsible for the major proportion of ischemic disease mortality changes. Treatment of instaured ischemic disease has a low influence.

Adult↗

PubMed1998

Changes in coronary risk profiles in employees after three years of multifactorial intervention.

This study was performed with the objective of assessing the effectiveness of the intervention at the work-site on lifestyle-related cardiovascular risk factors in four work-sites in Granada, Spain. Individualized face-to-face counseling was given to 1555 employees (1193 men and 362 women). After 3 years, a blinded assessment of the adequacy of the interventions was carried out. When changes in all employees were analysed together, ('per protocol' analysis) a non-significant reduction (-0.02%; 95% CI: -0.06 to +0.03%) in mean coronary risk was observed. We also distinguished between adequate and inadequate implementation of the intervention protocol. Observed changes in mean coronary risk were compared between both groups (adequate/inadequate implementation). Changes in mean coronary risk were beneficial only in the group that achieved an adequate level of intervention, with an observed significant mean reduction of risk of -0.12% (95% CI: -0.07 to -0.17) whereas changes were in the opposite direction in the other group with a mean change of +0.08% (95% CI: + 0.01 to + 0.16%). Work-site programs of health behaviour modification when appropriately implemented can attain although small, significant changes in cardiovascular risk profiles and thus be especially effective in achieving the population strategy of preventive cardiology.

Adult↗