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H Pastides

Publications and source records attributed to H Pastides.

At least 19 recordsLinked to original sources
PubMed1992

Case-control studies in pediatric epidemiology: parent surrogates and potential pitfalls of inaccurate and selective recall.

The case-control study is quite popular as a study design for exploring associations between risk factors and disease in pediatric epidemiology. Since data concerning exposures to the child are often collected through interviews with parents or other surrogates, researchers should be aware of the opportunities for bias due to inaccurate or incomplete recall. Methods which exist for the control of this problem are presented. These include: the selection of control groups with childhood conditions of similar etiologic uncertainty as the disease being studied; collecting exposure data from both parents; collection of data from children where possible; diligent interviewer training; reviewing clinical records; and use of validity scales. Strengths and weaknesses of these strategies are discussed.

Bias↗
PubMed1990

City directories as sources for survey work in low- and middle-income black communities.

Commercial directories and governmental lists of dwelling units in low income urban Black communities in four eastern cities were evaluated for completeness. With rare exceptions, less than 90 percent of dwelling units were included in any one list and no list adequately identified multiple dwelling unit structures. Since household income is likely to be lower among households in such structures, all lists tend to miss the very poor, i.e., those who may be at highest health risk.

Black or African American↗
PubMed1990

A case-control study of the relationship between smoking, diet, and gallbladder disease.

Eighty-four women with roentgenographically confirmed gallbladder disease and 171 control women hospitalized at a trauma hospital in Athens, Greece, were interviewed regarding demographic, reproductive, smoking, and dietary characteristics. A food-frequency approach was used to elicit consumption of 120 food or beverage items during the period before the onset of the current illness or hospitalization. The patients were substantially less likely to be regular cigarette smokers before the current admission. Additionally the patients reported significantly less frequent consumption of total items contained in the following food groups: sugars; pulses, nuts, beans; fish; and dairy products. On average they also consumed significantly fewer alcoholic beverages. On the other hand, the patients reported more frequent consumption of items in the following food groups: cereals, potatoes, fruits, meats, fats and oils, and coffee/tea. After controlling for confounding between food groups through multiple logistic regression models, the patients were still found to be less frequent consumers of vegetables and alcoholic beverages but more frequent consumers of potatoes and items in the cereal group. These analyses also confirmed the reduced likelihood of the patients being smokers.

Adult↗
PubMed1989

Intensive care unit patient follow-up. Mortality, functional status, and return to work at six months.

Six months after hospital discharge, we followed up 1545 patients who had received care in the general medical-surgical intensive care unit (ICU) of a tertiary care hospital. Vital status could not be ascertained for 200 of these patients. Of the 1345 former ICU patients for whom a determination of vital status could be made, 1261 (94%) were alive and 84 (6%) had died. Of those known to be living, 887 (70%) responded to a questionnaire regarding employment, functional, and social status. A large proportion of survivors less than 40 years of age had returned to work. Younger patients admitted to the hospital for elective surgery reported as much compromise of physical and psychological activity as did older patients admitted for emergency reasons. Older survivors reported an increase of interaction with family members and a decrease of social interaction with those other than family.

Adult↗
PubMed1989

How much soil do young children ingest: an epidemiologic study.

Sixty-four children aged 1-4 years were evaluated for the extent to which they ingest soil. The study followed the soil tracer methodology of S. Binder, D. Sokal, and D. Maughan (1986, Arch. Environ. Health, 41, 341-345). However, the present study included a number of modifications from the Binder et al. study. The principal new features were (1) increasing the tracer elements from three to eight; (2) using a mass-balance approach so that the contribution of food and medicine ingestion would be considered; (3) extending the period of observation from 3 days to 8 days; and (4) validating the methodology by having adult volunteers ingest known amounts of soil in a mass-balance validation study. The principal findings reveal the following. (1) The adult study confirmed the validity of the tracer methodology to estimate soil ingestion. (2) Of the eight tracers employed in the adult study, only Al, Si, and Y provided sufficient recovery data that was directly acceptably stable and reliable. (3) If food ingestion determinations were taken into consideration, the median estimates of soil ingestion from the eight tracers ranged from a low of 9 mg/day (Y) to a high of 96 mg/day (V); the median values of Al, Si, and Y, the three most reliable tracers, ranged from 9 mg/day to 40 mg/day. (4) One child had soil ingestion values ranging from 5 to 8 g/day, depending on the tracer. (5) If food ingestion had not been considered, the estimates of soil ingestion would have increased about two- to sixfold, depending on the tracer with Ti and Y being most affected by food intake. (6) Since soil and dust samples did not significantly differ in their levels of tracer elements, no reliable differentiation between the contribution of ingestion of dust and soil could be made. (7) These findings are generally consistent with the previously reported findings of Binder et al. (1986) and P. Clausing, B. Brunekreff, and J.H. van Wijnen (1987, Int. Arch. Occup. Med., 59, 73) if these latter studies are corrected for ingestion of tracers in food and medicine. The findings also account for the apparent discrepancy between the estimates from Al and Si and estimates based on Ti in previous studies. Thus the elevated estimates of soil ingestion by Ti were substantially reduced when food ingestion is considered.

Adult↗
PubMed1988

Spontaneous abortion and general illness symptoms among semiconductor manufacturers.

The risk of adverse reproductive outcomes was examined among semiconductor manufacturers. Personal interviews were conducted with manufacturing workers, spouses of male manufacturers, and an internal comparison group of non-manufacturing workers. Elevated spontaneous abortion ratios were observed for females working in the "diffusion" (38.9%; relative risk = 2.18, 95% confidence interval estimate = 1.1, 3.6) and photolithographic process (31.1%; relative risk = 1.75, 95% confidence interval estimate = 0.8, 3.3). Analysis of potential confounding did not substantially alter the findings. The potential for recall bias was also assessed; although the confidence interval for the comparison of diffusion and non-manufacturing workers no longer excluded 1.0, an excess risk was still reflected. No substantive differences in other reproductive outcomes were identified. Various general health symptoms were examined and reported more frequently among manufacturers than non-exposed. These results should be viewed as tentative until studies with larger numbers and more detailed exposure data are carried out.

Abortion, Spontaneous↗
PubMed1987

Validation of the mortality prediction model for ICU patients.

We tested recently developed admission and 24-h models of hospital mortality on 1,997 consecutive admissions to a general medical/surgical ICU. This study population was independent of the group used to develop the models. The admission prediction model estimated each patient's probability of hospital mortality based on seven routinely collected admission variables. The 24-h model utilized seven variables routinely available at 24 h in the ICU. The admission model accurately described the mortality experience of the new cohort, while the 24-h model did not. Advantages of the admission model are that it is evaluable at the time of ICU admission, is independent of ICU treatment, and can be used to stratify patients by severity of illness, thereby making ICU comparisons possible. Its excellent goodness-of-fit, correct classification rate, sensitivity, and specificity suggest that this model is now ready for multihospital testing.

Aged↗
PubMed1987

A comparison of methods to predict mortality of intensive care unit patients.

This paper presents results of the first study explicitly designed to compare three methods for predicting hospital mortality of ICU patients: the Acute Physiology Score (APS), the Simplified Acute Physiology Score (SAPS), and the Mortality Prediction Model (MPM). With respect to sensitivity, specificity, and total correct classification rates, these methods performed comparably on a cohort of 1,997 consecutive ICU admissions. In these patients from a single hospital, the APS overestimated and the SAPS underestimated the probability of hospital mortality. The MPM probabilities most closely matched the observed outcomes. Each method holds considerable promise for assessing the severity of illness of critically ill patients. The MPM should be particularly useful for comparing ICU performance, since it is independent of ICU treatment and can be calculated at the time a patient is admitted.

Diagnosis-Related Groups↗
PubMed1986

Enhanced bleeding with cefoxitin or moxalactam. Statistical analysis within a defined population of 1493 patients.

Most cases of beta-lactam-associated coagulopathy occur in patients with other risk factors. This study analyzed temporally related clinical bleeding events in 1493 patients who received one antibiotic for at least three days. Univariate and multivariate analyses controlled for condition variables (nutritional status, renal, hepatic, or hematologic dysfunction, intensive care unit stay) and treatment variables (use of antiplatelet agents, anticoagulants, vitamin K, antitumor chemotherapy or antiulcer therapy, steroids) that could have been associated with bleeding independently. Rates of bleeding ranged from 0% (chloramphenicol sodium succinate, vancomycin hydrochloride, erythromycin lactobionate) to 8.2% (cefoxitin) to 22.2% (moxalactam disodium). Multiple logistic regression analyses revealed that only moxalactam (odds ratio, 9.9) and cefoxitin (odds ratio, 2.1) exhibited significantly higher likelihoods of bleeding than other agents. This study statistically confirms increased risk of bleeding with moxalactam, heretofore reported only anecdotally. Cefoxitin may carry risks greater than previously believed.

Anti-Bacterial Agents↗
PubMed1985

An epidemiologic study of fibrocystic breast disease with reference to ductal epithelial atypia.

A case-control study of 255 women with fibrocystic breast lesions and 790 controls was conducted at two hospitals in New Haven, Connecticut during 1977-1979. Cases were found to weigh significantly less than controls, and were more likely than controls to have: a first-degree female relative with a history of breast cancer; a higher level of education; a recent history of regular gynecologic checkups; and (if under age 45 years) a later age at first pregnancy. They were less likely to have had a surgical menopause. The degree of ductal epithelial atypia in breast biopsy specimens was evaluated in order to see whether epidemiologic characteristics differed according to the degree of ductal atypia. The only variable to show a linear relationship with ductal atypia was a recent history of regular gynecologic checkups; those with no or minimal atypia were more likely to have had recent checkups than those with high atypia scores. This study thus gives no evidence that known risk factors for breast cancer are more strongly associated with fibrocystic breast disease with a high degree of atypia than with fibrocystic breast disease with a low degree of atypia. It also provides data to support the belief that women having frequent gynecologic checkups are more likely to be included as cases in case-control studies of fibrocystic breast disease, and particularly in the groups with no or minimal atypia, than those not having frequent checkups.

Adult↗
PubMed1985

Applications of microcomputer spreadsheet packages as adjuncts to multiple logistic regression analysis.

This paper illustrates how a microcomputer spreadsheet package can be used by epidemiologists to facilitate the computation of multiple logistic regression (MLR) probabilities, as well as odds ratios and associated confidence intervals, given the coefficients of the MLR model. By formatting a spreadsheet, data entry is greatly simplified, and computations are accomplished without any arithmetic manipulations on the part of the user. This approach makes it feasible for clerical support staff to assist in the computation of seemingly complex expressions. The increasing availability of microcomputers in clinical and research settings suggests that numerous analytic applications are amenable to this approach, thereby decreasing reliance on mainframe computers and desk-top calculators.

Computers↗
PubMed1985

A method for predicting survival and mortality of ICU patients using objectively derived weights.

Data at ICU admission and after 24 h in the ICU were collected on 755 patients, to derive multiple logistic regression models for predicting hospital mortality. The derived models contained relatively few and easily obtained variables. The weight associated with each variable was determined objectively. There were seven admission variables, none of which were treatment dependent, and seven 24-h variables reflecting treatments and patients' conditions in the ICU. Predicted outcomes using these two models were closely correlated with actual outcome. Theoretically, a predictive model would be useful to physicians for triage decisions as well as determining aggressiveness of care through discussions with families, determining utilization of ICU facilities, and objectively comparing different ICUs. This research represents an initial attempt to develop models that are not based on subjectively determined weights.

Adolescent↗
PubMed1985

Prevalence and correlates of diabetes, hypertension and diaphragmatic hernia among an epileptic population.

The occurrence of diabetes, hypertension, and diaphragmatic hernia was investigated in an institutionalized population of long-term epileptics. Review of medical records determined the prevalence ratio of diabetes to be about 1.6% and the prevalence of hypertension to be about 2.3%. Both of these estimates are significantly lower than the rates in the general US population. The prevalence of diaphragmatic hernia among females (4.8%) was found to be significantly higher than the general population rate, but the corresponding ratio among males (3.6%) was not. Associations with major drugs used were subsequently investigated using a case-control methodology. Implications for etiologic research are discussed.

Adolescent↗
PubMed1985

Diaphragm method contraceptors: implications for service organization and delivery.

Despite dissemination of modern contraceptive techniques among college women, unplanned pregnancy and pregnancy termination rates remain a major health issue. An investigation of 495 college women who use the diaphragm method of contraception was conducted in order to estimate pregnancy occurrence, to better understand factors related to successful use, and to profile service utilization patterns. Data were collected by medical record audit and client survey. Fifteen percent of the diaphragm clients reported a diaphragm-related pregnancy; clinical effectiveness was estimated to be 88% with a rate of 9.75 pregnancies per 100 woman years of diaphragm use. A variety of demographic, personal history, and behavioral variables were found to be related to three dependent variables: pregnancy, consistent diaphragm use, and accurate diaphragm use. Review of clinic service utilization for this group of patients demonstrated considerable resource use, including frequent switching of prescription contraception methods. Considering all pregnancies, diaphragm related or not, 27% of the study subjects reported at least one unplanned pregnancy. Abortion was elected in 98% of these cases. There is general agreement about the need to focus on education, information, and service measures to reduce the incidence of unintended fertility. Many universities have family planning services available, yet unsuccessful outcome continues to be a concern. Specific and practical protocols for service implementation need clearer definition. Thus, the implications of this research for the content and organization of clinic services are discussed with reference to counseling and education and other systems strategies.

Abortion, Induced↗
PubMed1985

Uses of the case-control and cohort epidemiological approaches in pediatric practice and research.

Increasing reliance is being placed on the use of quantitative epidemiological methods in the conduct and evaluation of pediatric research. The basic design features of two common types of observational studies, the case-control study and the cohort study, are reviewed. Advantages and disadvantages of these two study designs are discussed with emphasis on aspects such as the selection of comparison groups, avoiding selection and recall bias, gathering exposure information, controlling for potentially confounding factors, and methods of analysis. Appreciation of the salient features of these study design approaches should aid the clinician/researcher in the conduct of research endeavors as well as in critically reviewing the medical literature.

Adolescent↗