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PubMedDate not supplied

Evaluating performance outcomes measurement systems: concerns and considerations.

In today's managed care healthcare environment, there is a need for hospitals and physician groups alike to know the true quality and costs of healthcare services provided to patients. As the movement toward having providers accept risk via financial capitation escalates, quality improvement professionals involved in outcomes management are increasingly being asked to investigate information sources and systems that can prove helpful in managing effectively within these limitations. As a result, there is a high degree of interest in comparative performance outcomes measurement data based on risk-adjusted and severity-adjusted data. This article explains the key features of performance outcomes measurement systems and notes concerns that should be considered when evaluating these software systems for selection.

Benchmarking↗
PubMed1989

Adjusting the 1980 census of population and housing.

"In 1980, several cities and states sued the U.S. Census Bureau to correct census results. This correction would adjust for the differential undercounting of Blacks and Hispanics, especially in cities. In this article, the authors, each of whom testified for New York City and State in their joint lawsuit against the Census Bureau, describe the likely pattern of the undercount and present a method to adjust for it." The authors describe available methods for data adjustment and introduce a regression-based composite method of adjustment, which is used to estimate the undercounts for 66 areas. "As expected, we find that the highest undercount rates are in large cities, and the lowest are in states and state remainders with small percentages of Blacks and Hispanics. Next, we analyze how sensitive our estimates are to changes in data and modeling assumptions. We find that these changes do not affect the estimates very much. Our conclusion is that regardless of whether we use one of the simple methods or the composite method and regardless of how we vary the assumptions of the composite method, an adjustment reliably reduces population shares in states with few minorities and increases the shares of large cities."

Black or African American↗
PubMed1999

Monte Carlo Markov chain methods for genome screening.

We used Monte Carlo Markov chain (MCMC) methods to analyze a quantitative trait, MAO level, and a discrete trait, Collaborative Study on the Genetics of Alcoholism (COGA) alcoholism. Segregation, linkage, and haplotype sharing were analyzed and effects of marker map features were examined. For MAO, modest signals were found on chromosomes 1 and 17 for raw data, and 15 for covariate-adjusted data. For alcoholism, a strong signal was found on chromosome 1 with modest signals on chromosomes 4 and 10.

Alcoholism↗
PubMed1997

The distribution of selenium and mortality owing to acquired immune deficiency syndrome in the continental United States.

A hypothesis has been proposed that Selenium (Se) concentration in the environment as measured by its uptake by alfalfa, which sorbs Se from the soil in proportion to what is present, exerted an apparent effect on incidence of (acquired immune deficiency syndrome) AIDS such that AIDS' mortality within the conterminous United States was lower where the Se quantity in the soil was high than where the amount was low. The object of this study was to test this hypothesis for statistical significance and to discover whether the apparent pattern of AIDS mortality in relation to Se distribution holds true with respect to all ages, both races (Black and White), and both genders. The statistical analysis employed was analysis of variance. Age-specific data as well as age-adjusted data were subject to statistical analysis. Ages where AIDS mortality rates per 100,000 were greatest were in the range from 25-54 yr for low-, medium-, and high-Se areas of the US. Black mortality owing to AIDS showed highly statistically significant results for the three Se regions, both genders, and six age groups, whereas White mortality was not as significantly affected by Se. A hypothesis is proposed that the Black population during the last decade or so has been less migratory than the White population. Thus, their food supply and hence its Se content have been more stable than that of the White population, which is more prone to consume imported foods to unknown Se content and be more migratory. A second hypothesis is advanced that suggests that medical care is not equally available to the poor and especially poor Blacks. Black men and women die at a greater death rate than do Whites. This implies that a lack of medical care is the true cause. This article suggests that a pattern exists between the geographical distribution of Se using alfalfa as a dietary guide and AIDS' mortality such that an inverse relationship persists between Se quantity in an area and AIDS' mortality in the same area.

Acquired Immunodeficiency Syndrome↗
PubMed1993

Genetic parameter estimates and expected progeny differences for mature size in Angus cattle.

Mature size records collected on Angus cows of 5 to 12 yr of age were used to estimate heritabilities, genetic correlations, and EPD for mature weight and mature height. A total of 256 sires were evaluated using mature size data collected on 2,732 daughters. Data were analyzed using REML procedures with a two-trait sire model to estimate sire and error variances for mature weight and height. Models with and without adjustment of weight for body condition score were investigated. The linear model for weight and height included fixed herd-year-month the records were taken, sire genetic group, random sire, and residual error. Using unadjusted mature weights, heritabilities were .48 +/- .10 for weight and .83 +/- .11 for height. When condition score adjustments were made, heritability estimates were .45 +/- .10 for weight and .83 +/- .11 for height. Genetic (phenotypic) correlations between weight and height were .78(.58) for adjusted data and .66(.54) with no adjustment. Spearman rank correlations between sire EPD for adjusted and unadjusted data were .94 for weight and .99 for height. Two-trait models of mature cow weight with immature weights (birth weight, 205-d weight, 365-d weight) were used to assess genetic relations among mature and immature cow weights. Genetic correlations between mature weight and immature weights were .57 with birth weight, .62 with 205-d weight, and .45 with 365-d weight.

Animals↗
PubMed2006

Laparoscopic versus open gastric bypass for morbid obesity: a multicenter, prospective, risk-adjusted analysis from the National Surgical Quality Improvement Program.

OBJECTIVE: To compare laparoscopic versus open gastric bypass procedures with respect to 30-day morbidity and mortality rates, using multi-institutional, prospective, risk-adjusted data. SUMMARY BACKGROUND DATA: Laparoscopic Roux-en-Y gastric bypass for weight loss is being performed with increasing frequency, partly driven by consumer demand. However, there are no multi-institutional, risk-adjusted, prospective studies comparing laparoscopic and open gastric bypass outcomes. METHODS: A multi-institutional, prospective, risk-adjusted cohort study of patients undergoing laparoscopic and open gastric bypass procedures was performed from hospitals (n = 15) involved in the Private Sector Study of the National Surgical Quality Improvement Program (NSQIP). Data points have been extensively validated, are based on standardized definitions, and were collected by nurse reviewers who are audited for accuracy. RESULTS: From 2000 to 2003, data from 1356 gastric bypass procedures was collected. The 30-day mortality rate was zero in the laparoscopic group (n = 401), and 0.6% in the open group (n = 955) (P = not significant). The 30-day complication rate was significantly lower in the laparoscopic group as compared with the open group: 7% versus 14.5% (P < 0.0001). Multivariate logistic regression analysis was performed to control for potential confounding variables and showed that patients undergoing an open procedure were more likely to develop a complication, as compared with patients undergoing an laparoscopic procedure (odds ratio = 2.08; 95% confidence interval, 1.33-3.25). Propensity score modeling revealed similar results. A prediction model was derived, and variables that significantly predict higher complication rates after gastric bypass included an open procedure, a high ASA class (III, IV, V), functionally dependent patient, and hypertension as a comorbid illness. CONCLUSIONS: Multicenter, prospective, risk-adjusted data show that laparoscopic gastric bypass is safer than open gastric bypass, with respect to 30-day complication rate.

Adult↗
PubMed2001

False positive outcomes and design characteristics in occupational cancer epidemiology studies.

BACKGROUND: Recently there has been considerable debate about possible false positive study outcomes. Several well-known epidemiologists have expressed their concern and the possibility that epidemiological research may loose credibility with policy makers as well as the general public. METHODS: We have identified 75 false positive studies and 150 true positive studies, all published reports and all epidemiological studies reporting results on substances or work processes generally recognized as being carcinogenic to humans. All studies were scored on a number of design characteristics and factors relating to the specificity of the research objective. These factors included type of study design, use of cancer registry data, adjustment for smoking and other factors, availability of exposure data, dose- and duration-effect relationship, magnitude of the reported relative risk, whether the study was considered a 'fishing expedition', affiliation and country of the first author. RESULTS: The strongest factor associated with the false positive or true positive study outcome was if the study had a specific a priori hypothesis. Fishing expeditions had an over threefold odds ratio of being false positive. Factors that decreased the odds ratio of a false positive outcome included observing a dose-effect relationship, adjusting for smoking and not using cancer registry data. CONCLUSION: The results of the analysis reported here clearly indicate that a study with a specific a priori study objective should be valued more highly in establishing a causal link between exposure and effect than a mere fishing expedition.

Bias↗
PubMedDate not supplied

Evaluation and correction for a 'training effect' in the cognitive assessment of older adults.

BACKGROUND: Repeated administration of psychometric instruments frequently results in a higher score on retesting, the so-called training effect. Yet, a training effect has been poorly considered in longitudinal studies of cognitive changes in older persons. METHODS: We investigated the presence, magnitude and potential adjustments for training effect in the older participants of the Systolic Hypertension in the Elderly Program (SHEP). SHEP evaluated the cognitive status effects of a diuretic-based treatment of isolated systolic hypertension versus placebo. Changes in the short Comprehensive Assessment and Referral Evaluation (short-CARE) questionnaire score, from baseline through 4 years of follow-up, were assessed in 4,718 participants. In this study, we used two regression techniques to adjust data for the training effect. RESULTS: In both study groups, a training effect was evident as a progressive improvement in the short-CARE score throughout year 1. Thereafter, cognitive scores tended to deteriorate, more in the placebo than in the active treatment group (p = 0.055). When follow-up scores were adjusted based upon baseline data, the difference between the study groups reached statistical significance (p = 0.019), but the apparent overall trend towards deterioration in cognitive score was no longer observed. Adjustment of baseline data preserved this apparent temporal course, but did not improve the discrimination between the two study groups (p = 0.165). CONCLUSIONS: In SHEP, repeated cognitive assessments were likely biased by a training effect which could be only partially corrected by statistical techniques. Studies of changes in the cognitive status of older persons should be designed appropriately to estimate and minimize the consequences of a training effect in follow-up data.

Aged↗
PubMed2006

Psychological workload and weight gain among women with and without familial obesity.

OBJECTIVE: High job demands and low job influence may be associated with subsequent weight gain. Predisposition to obesity may further modify such associations. The purpose of the study was to determine whether familial predisposition to obesity modified associations between psychological workload and 6-year weight changes among nurses. RESEARCH METHODS AND PROCEDURES: A total of 6404 Danish nurses 45 to 65 years old, who belonged to the workforce in both 1993 and 1999, answered a questionnaire on psychological workload, body weight, and familial obesity. Women were considered to be predisposed to obesity if they were overweight and had at least one obese parent. Parents' body shape was reported using pictograms. RESULTS: An increased psychological workload, reflected by high job demands and low influence in job, was associated with an increased body weight. This was particularly the case for nurses being predisposed to obesity, suggesting a synergy between familial obesity predisposition and the psychological workload environment. An interaction test among job demands, familial predisposition to obesity, and weight gain on adjusted data was made. The test showed p = 0.05. The adjusted interaction test among influence in job, familial predisposition to obesity, and weight gain showed p = 0.02. Predisposed nurses who were busy in their job gained 4.4 kg, whereas other nurses gained only 3.2 kg during the 6 years. Similarly, nurses predisposed to obesity with low influence in job had a higher body weight gain (5.4 vs. 3.2 kg) compared with other nurses. DISCUSSION: High psychological workload due to high job demands and low influence in job seems to predict weight gain in general and, in particular, among those nurses with a familial predisposition to obesity.

Causality↗
PubMed1998

Increasing prevalence of overweight among US low-income preschool children: the Centers for Disease Control and Prevention pediatric nutrition surveillance, 1983 to 1995.

OBJECTIVE: To determine whether the prevalence of overweight in preschool children has increased among the US low-income population. DESIGN: Analysis using weight-for-height percentiles of surveillance data adjusted for age, sex, and race or ethnicity. SETTING: Data from 18 states and the District of Columbia were examined. SUBJECTS: Low-income children <5 years of age who were included in the Centers for Disease Control and Prevention Pediatric Nutrition Surveillance System. RESULTS: The prevalence of overweight increased from 18.6% in 1983 to 21.6% in 1995 based on the 85th percentile cutoff point for weight-for-height, and from 8.5% to 10.2% for the same period based on the 95th percentile cutoff point. Analyses by single age, sex, and race or ethnic group (non-Hispanic white, non-Hispanic black, and Hispanic) all showed increases in the prevalence of overweight, although changes are greatest for older preschool children. CONCLUSION: Overweight is an increasing public health problem among preschool children in the US low-income population. Additional research is needed to explore the cause of the trend observed and to find effective strategies for overweight prevention beginning in the preschool years.

Body Height↗
PubMed1975

Incidence of cancer in United States blacks.

Incidence rates for the black population of six Standard Metropolitan Statistical Areas in the United States are examined using data collected in the Third National Cancer Survey, 1969 to 1971. For all sites combined, black males had the highest rates among the four major race-sex groups; black females had the lowest rates. For fourteen common sites accounting for 80% of the cancers among blacks, black/white ratios, survival data, trends between 1935 and 1969, and geographic variation are presented. United States black data adjusted to an African Standard are compared with similar data from Nigeria, Rhodesia, and South Africa.

Adolescent↗
PubMed1989

Longitudinal comparisons of families who have adopted children with mental retardation.

Families with adopted mentally retarded children were contacted 3 years after original study to assess longer term adjustment. Data from 80% of the original sample indicated continued good family adjustment on a number of measures, including the Holroyd Questionnaire on Resources and Stress. Only 2 of 44 children were no longer living with their adoptive/foster parents for reasons related to adjustment difficulties. In contrast, 12 of the families had adopted or were fostering additional children, 11 of whom had handicapping conditions. These data indicate a positive prognosis for adoption as a desirable option for the rearing of children with mental retardation.

Adolescent↗
PubMed1995

Development and reproducibility of a food frequency questionnaire to assess diets of older children and adolescents.

OBJECTIVE: To develop a self-administered food frequency questionnaire for older children and adolescents and to demonstrate reproducibility over a 1-year period. DESIGN: The youth/adolescent questionnaire (YAQ) was based on the validated Nurses' Health Study food frequency questionnaire and was developed to reflect the eating habits of this age group. SUBJECTS: The multiethnic sample consisted of 179 youths (ages 9 to 18 years) who completed the questionnaire twice, 1 year apart. STATISTICAL ANALYSIS: Pearson correlation coefficients were calculated on nutrient data adjusted in relation to energy intake and on unadjusted food data. RESULTS: Reproducibility for nutrients ranged from .26 for protein and iron to .58 for calcium, and for foods it ranged from .39 for meats to .57 for soda. Mean reproducibility was higher among girls than boys for energy and nutrients and for foods; no consistent pattern was observed for age. CONCLUSION: A self-administered food frequency questionnaire has a reasonable ability to assess the eating habits of older children and adolescents over time.

Adolescent↗
PubMed2001

Standardisation of temperature observed by automatic weather stations.

Daily mean, maximum and minimum surface air temperature data were gathered from a network of automatic weather stations (AWS) within the Moor House National Nature Reserve in northern England. Five AWS were installed next to the official Environmental Change Network weather station at Moor House. Data were compared graphically and correction constants were calculated to adjust data from each AWS to the standard of the official station by optimising the concordance correlation coefficient. Each corrected station was re-located next to one of five in-situ stations in and around the reserve, allowing correction of all temperature sensors to a common standard. The mean error associated with measured daily mean, maximum and minimum temperature for each sensor does not exceed +/- 0.2 K. The procedure quantifies a source of systematic measurement error, improving the identification of spatial temperature differences between stations.

Air↗
PubMed2004

Time patterns and seasonal mismatch in suicide.

OBJECTIVE: Physical time-givers may have a modifying effect on the time patterns of death from suicide. METHOD: Data on a total of 1397 suicides in Finland over a year were collected using the method of psychological autopsy. We linked versatile information on each individual to meteorological data adjusted for local weather conditions, and to the universal astronomic data. RESULTS: The number of suicides with seasonal mismatch was greater than the expected in the northernmost region of the country (P = 0.03). The northern location was the most significant predictor of such suicides (P = 0.001). They were associated with the changes in ambient temperature during the preceding day (P < 0.00001), the changes to colder preceding suicides in the spring. CONCLUSION: Our findings show that mismatch between the changes in ambient temperature and those in the length of day may precede death from suicide in some individuals.

Adolescent↗
PubMed1991

Pathology reevaluation of the Kociba et al. (1978) bioassay of 2,3,7,8-TCDD: implications for risk assessment.

The chronic bioassay of 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD) reported in 1978 by Kociba et al. has been considered to be the primary evidence supporting its carcinogenicity, and is the basis for most dioxin regulations in North America and Western Europe. Because the histopathological criteria for proliferative lesions in the rat liver have changed significantly since 1978, a reevaluation of the liver slides was conducted recently by an independent panel of pathologists. Using current National Toxicology Program criteria, their study showed, in contrast to the original findings, that about two-thirds fewer tumors were present in the livers of female Sprague-Dawley rats. The no-observed-adverse-effect level (NOAEL) for hepatocellular carcinomas was 0.01 micrograms/kg/d rather than 0.001 micrograms/kg/d, which had been reported in 1978. In light of these significant findings, a quantitative dose-response assessment of 2,3,7,8-TCDD was undertaken to predict the potential carcinogenic risks to humans. Risk-specific doses (RsDs) and cancer potency factors (CPFs) were calculated by applying the linearized multistage (LMS) model to the combined incidences of hepatocellular carcinomas and adenomas, classified in accordance with the 1990 histopathological criteria. Based on the weight of evidence regarding the mechanism of action of 2,3,7,8-TCDD, body weight rather than surface area was selected as the appropriate means for scaling rodent data to predict the human response. Using the survival-adjusted data, the RsD for a 1 in 1,000,000 (10(-6)) plausible upper bound (95%) lifetime incremental cancer risk was 370 fg/kg/d based only on the incidence of hepatocellular carcinomas, and 100 fg/kg/d when hepatocellular carcinomas and adenomas were combined. The corresponding upper-bound (95%) CPFs were 2700 and 9700 (mg/kg/d)-1, respectively. These results indicate that the carcinogenic risk to humans from exposure to 2,3,7,8-TCDD is at least 16-fold lower than previous estimates derived from the Kociba et al. (1978) bioassay.

Animals↗
PubMed2003

On the importance of age-adjustment methods in ecological studies of social determinants of mortality.

OBJECTIVE: To illustrate the potential sensitivity of ecological associations between mortality and certain socioeconomic factors to different methods of age-adjustment. DATA SOURCES: Secondary analysis employing state-level data from several publicly available sources. Crude and age-adjusted mortality rates for 1990 are obtained from the U.S. Centers for Disease Control. The Gini coefficient for family income and percent of persons below the federal poverty line are from the U.S. Bureau of Labor Statistics. Putnam's (2000) Social Capital Index was downloaded from http://www.bowlingalone.com; the Social Mistrust Index was calculated from responses to the General Social Survey, following the method described in Kawachi et al. (1997). All other covariates are obtained from the U.S. Census Bureau. STUDY DESIGN: We use least squares regression to estimate the effect of several state-level socioeconomic factors on mortality rates. We examine whether these statistical associations are sensitive to the use of alternative methods of accounting for the different age composition of state populations. Following several previous studies, we present results for the case when only mortality rates are age-adjusted. We contrast these results with those obtained from regressions of crude mortality on age variables. PRINCIPAL FINDINGS: Different age-adjustment methods can cause a change in the sign or statistical significance of the association between mortality and various socioeconomic factors. When age variables are included as regressors, we find no significant association between mortality and either income inequality, minority racial concentration, or social capital. CONCLUSIONS: Ecological associations between certain socioeconomic factors and mortality may be extremely sensitive to different age-adjustment methods.

Adolescent↗
PubMed1982

Age-adjusted mortality rate and regional distribution for prostatic carcinoma in Italy between 1969 and 1978.

The age-adjusted mortality rate for prostatic carcinoma in Italy between 1969 and 1978 was calculated, as was the regional distribution for this disease. An overall increase in mortality was found, but the increase of the age-adjusted data was not statistically significant. The regional distribution of age-adjusted mortality rate showed a difference between northern and southern Italy, even when errors that can affect these findings were taken into consideration. At present, however, the size of these errors is not known. Such factors should not, however, prevent development of useful information and indications, but they should not be overlooked in an analytical interpretation of the data.

Adult↗