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PubMedDate not supplied

A Hawthorne strategy: implications for performance measurement and improvement.

The Hawthorne experiments are a backdrop for diverse studies assessing the impact of treatment and experimentation on human and organizational performance. The Hawthorne effect is used to describe the positive impact on behavior that sometimes occurs in a study or experiment as a result of the interest shown by the experimenter in humans who are being treated, studied, or observed. We propose that the Hawthorne effect can be viewed as an active construct to develop a coherent strategy for performance improvement. We propose a "Hawthorne strategy" that transcends the Hawthorne effect in that it offers an approach to improving performance indefinitely. This strategy uses external observations of performance to increase internal commitment to performance improvement. The focus of individual responsibility increases as does the perceived connection between individual efforts and external performance improvement. The sense of accountability is maintained by institutional recognition and periodic reinforcement of individual behaviors that contribute to performance improvement. A successful Hawthorne strategy encourages providers of care to be evaluators of their performance as individuals, as members of groups, and as members of institutions.

Effect Modifier, Epidemiologic↗
PubMed1998

A statistical model that takes into account patient heterogeneity in decision making.

Statistical evaluation of clinical treatments or preventive medicine has profoundly contributed to decision making in medical fields such as with the acceptance of new treatment methods and health promotion policies. It is crucial in such decision making to find a correct statistical model to treat a surprisingly large variety of patients, or a heterogeneous group of patients, even with the same diagnosis. In diseases such as cancer, cardiovascular disease or diabetes, patients are often followed up to certain endpoints and these data are frequently analyzed by logrank tests or Cox-models to evaluate treatment effects. Although these methods have been widely accepted and extensively studied, we are sometimes faced with problems in applying these methods when the heterogeneity of patients is large and a lot of prognostic factors affecting the endpoints have to be considered. Based on the results of the analyses of survival data from more than 6,000 gastric cancer patients, it is revealed that the stratified logrank test may suffer serious power loss, even though primary prognostic factors are used as stratified factors. A so-called 'piecewise linear Cox regression method' for properly treating the heterogeneity of patients is introduced and extensively studied. This method is shown to be appropriate for patient groups with a high degree of heterogeneity such as the gastric cancer patients. The same method is, in principle, applicable to patients of other diseases, too, using statistical software such as SAS, BMDP and etc.

Algorithms↗
PubMed1999

The controversy of significance testing: misconceptions and alternatives.

The current debate about the merits of null hypothesis significance testing, even though provocative, is not particularly novel. The significance testing approach has had defenders and opponents for decades, especially within the social sciences, where reliance on the use of significance testing has historically been heavy. The primary concerns have been (1) the misuse of significance testing, (2) the misinterpretation of P values, and (3) the lack of accompanying statistics, such as effect sizes and confidence intervals, that would provide a broader picture into the researcher's data analysis and interpretation. This article presents the current thinking, both in favor and against, on significance testing, the virtually unanimous support for reporting effect sizes alongside P values, and the overall implications for practice and application.

Bias↗
PubMed1999

The nocebo effect: do no harm.

The nocebo effect creates negative expectations about symptoms and can have devastating influence on patient recovery. Just as the placebo effect works by making patients believe they will get better, the nocebo effect can serve to make patients worse. Two case histories are presented in which patients were assigned diagnoses without objective physical findings. This resulted in poor outcomes. Physicians should avoid assigning a diagnosis without objective physical evidence and thus avoid creating the nocebo effect in patients.

Adult↗
PubMed1999

Misclassification in case-control studies of gene-environment interactions: assessment of bias and sample size.

In studies of gene-environment interactions, exposure misclassification can lead to bias in the estimation of an interaction effect and increased sample size. The magnitude of the bias and the consequent increase in sample size for fixed misclassification probabilities are highly dependent on the prevalence of the misclassified factor and on the interaction model. This paper describes a relatively simple approach to assess the impact of misclassification on bias in the estimation of multiplicative or additive interactions and on sample size requirements. Applications of this method illustrate that even small errors in the assessment of environmental or genetic factors can result in biased interaction parameters and substantially increased sample size requirements that can compromise the feasibility of the study. Also, an example is provided where nondifferential misclassification biases an additive interaction parameter away from the null value, even under conditions where a multiplicative interaction parameter will always be biased toward the null value. Efforts to improve the accuracy in measuring both genetic and environmental factors are critical for the valid assessment of gene-environment interactions in case-control studies.

Benzo(a)pyrene↗
PubMed2000

The "Hawthorne effect"--what did the original Hawthorne studies actually show?

The "Hawthorne effect" is often mentioned as a possible explanation for positive results in intervention studies. It is used to cover many phenomena, not only unwitting confounding of variables under study by the study itself, but also behavioral change due to an awareness of being observed, active compliance with the supposed wishes of researchers because of special attention received, or positive response to the stimulus being introduced. At times, the term seems to be used as a social equivalent to "placebo effect". In social research, there is much critical literature indicating that, in general, the term "Hawthorne effect" should be avoided. Instead of referring to the ambiguous and disputable Hawthorne effect when evaluating intervention effectiveness, researchers should introduce specific psychological and social variables that may have affected the outcome under study but were not monitored during the project, along with the possible effect on the observed results.

Effect Modifier, Epidemiologic↗
PubMed1996

Side effects from influenza vaccination: differences between returned and random surveys.

Annually vaccinated Air National Guard members were surveyed by return of questionnaire in 1991 (20.5%) and in 1992 by random phone survey (23.5%). By returned questionnaire the sample reported any side effects at the rate of 48.1%; by randomly telephoned sample a significantly lower rate, 37.7% (p < 0.02), was reported. An inverse relationship existed between age and return of the questionnaire, present only in males, despite an increased rate of reporting of side effects in the younger ages. Females reported a significantly higher rate of side effects than males by return of questionnaire in all age groups and for the sample as a whole (p < 0.03). In the randomized survey the age effect disappeared, except for the tendency for the oldest group to report fewer side effects than the other age groups in their aggregate (p < 0.07). The higher reporting rate for females was less apparent by random survey but remained as a trend (p = 0.08; odds ratio 1.398; 95% confidence interval = 0.776-4.049).

Adolescent↗
PubMedDate not supplied

Outcome assessment: suggestions for agency practice.

Managed care proponents emphasize outcome research to determine the cost-effectiveness of interventions, suggesting the use of multimeasurement procedures that will assess both specific and general effects of interventions. Although most agencies can perform outcome assessment and outcome management, they have difficulty conducting meaningful outcome research. This articles provides an introduction to outcome research; discusses the concepts of statistical significance, effect size, and the meaningfulness of effects; and emphasizes the need for client value-based judgments regarding the effectiveness of interventions. To encourage agencies to use client-completed outcome assessment procedures, the steps needs to effectively do so are outlined.

Child↗
PubMed2000

Major gene effect on body mass index: the role of energy intake and energy expenditure.

The evidence for a major gene for body mass index (BMI) was investigated using complex segregation analysis (POINTER) in 1691 individuals belonging to 432 nuclear families residing in the Chittoor district of Andhra Pradesh, India. Since the BMI is significantly correlated with energy intake (EI) and energy expenditure of activity (EEA), the effects of each were removed from the BMI using regression analysis, and the segregation analysis was repeated on the energy-adjusted BMI. For BMI, a putative major locus could not be ruled out, and the effect (q = 0.25, accounting for 37% of the phenotypic variance) was remarkably similar to that reported in Western populations. After adjusting the BMI for EI and EEA, however, no evidence in support of a major gene could be observed, suggesting either that EI and EEA mediate the expression of the major gene effect on BMI, or that the same major gene may influence both traits. The pleiotropy hypothesis was further explored using a simple bivariate familial correlation model, in which the significance of familial cross-trait correlations (e.g., BMI in parents with BMI as predicted from the energy variables in the offspring) was examined. The cross-trait resemblance between the two measures was significant for all biological relatives, verifying the presence of shared heritable determinants (i.e., the same gene[s] and/or familial environments) accounting for 58% of the covariation. The significant cross-trait spouse correlations further suggested that at least part of the cross-trait resemblance may be due to shared environmental factors. Therefore, we conclude that there is strong evidence for shared genetic effects between BMI and the energy variables.

Adolescent↗
PubMed2000

Expectations among the elderly about nursing home entry.

OBJECTIVE: To assess whether the covariates that explain expectations of nursing home entry are consistent with the characteristics of those who enter nursing homes. DATA SOURCES: Waves 1 and 2 of the Assets and Health Dynamics Among the Oldest Old (AHEAD) survey. STUDY DESIGN: We model expectations about nursing home entry as a function of expectations about leaving a bequest, living at least ten years, health condition, and other observed characteristics. We use an instrumental variables and generalized least squares (IV-GLS) method based on Hausman and Taylor (1981) to obtain more efficient estimates than fixed effects, without the restrictive assumptions of random effects. PRINCIPAL FINDINGS: Expectations about nursing home entry are reasonably close to the actual probability of nursing home entry. Most of the variables that affect actual entry also have significant effects on expectations about entry. Medicaid subsidies for nursing home care may have little effect on expectations about nursing home entry; individuals in the lowest asset quartile, who are most likely to receive these subsidies, report probabilities not significantly different from those in other quartiles. Application of the IV-GLS approach is supported by a series of specification tests. CONCLUSIONS: We find that expectations about future nursing home entry are consistent with the characteristics of actual entrants. Underestimation of risk of nursing home entry as a reason for low levels of long-term care insurance is not supported by this analysis.

Activities of Daily Living↗
PubMed2001

[Does statin therapy reduce the risk of stroke? A meta-analysis].

Large scale clinical trials have clearly demonstrated that the HMG-CoA reductase inhibitors (statins) reduce cardiovascular mortality by about 30%. The specific benefit on stroke prevention remains however to be determined. We reviewed all controlled clinical trials comparing statins versus placebo in primary and secondary prevention of cardiovascular disease. We identified 13 studies including 4S, CARE, WOSCOPS and LIPID. More than 32000 patients were randomized. The meta-analysis was performed using relative risk as treatment effect parameter. Statin treatment induced a significant relative risk reduction (RRR) of 24% (95% CI [12%-34%]) for stroke (2.1% vs 2.8%). RRR achieved 25% (95% CI [17%-32%]) for cardiovascular mortality and 34% (95% CI [30%-38%]) for myocardial infarction, without heterogeneity between trials. Stroke was reduced by 25% in secondary prevention, and by 15% in primary prevention, without significant heterogeneity between them. RRR of stroke was similar with pravastatin (RRR=0.79, p=0.0038) and with simvastatin (RRR=0.71, p=0.049). The effect model analysis (relationship between annual incidence of events in treated group versus placebo group in each trial) showed that RRR was constant whatever the baseline risk. These results are in favor of a preventive efficacy of statin treatment against stroke in middle aged patients with coronary heart disease. Complementary information will be needed to clarify the mechanism of this beneficial effect and to demonstrate statin efficacy in a population with a higher risk of stroke such as the elderly.

Age Distribution↗
PubMed2001

[Cause of non-pertinent hospital stays: interobserver concordance using the French version of the Appropriateness Evaluation Protocol].

BACKGROUND: The modified French version of the Appropriateness Evaluation Protocol (AEPf) has been validated. Inappropriate days according to simple medical and technical criteria are identified with this tool. The aim of this study is to highlight the interest of investigating the reasons for inappropriate days and to assess the inter-observers reliability of the questionnaire developed for this purpose. METHODS: This questionnaire collects on one hand the needs of patients - distinguishing health care and accommodation needs - and on the other hand the reasons for inappropriate hospital days. The data were collected from January to September 1998 in nine voluntary medical and surgical departments. For each day of study randomly selected, each inappropriate hospital day according to AEPf has been included. Data were collected by two health professionals (a nurse and a physician), using a concurrent design. RESULTS: The reliability of the over-ride option of the appropriateness assessment of the 345 hospital days was good (overall Kappa coefficient: 0.66; 95% CI: 0.55-0.78). The comparison of the two expert judgments on health care needs fulfilled during the hospital day was acceptable; the Kappa coefficient was 0.62 (95% CI: 0.52-0.72). The reliability of expert assessment on patient accommodation needs (home, housing facilities or hospital) was good (Kappa coefficient: 0.67; 95% CI: 0.60-0.75). When hospital was not the accommodation the most adapted for patient, the reliability of the reasons for inappropriate days was high (Kappa coefficient: 0.75; 95% CI: 0.61-0.80). Kappa coefficients were different between hospitals, indicating a center effect. CONCLUSION: This instrument has been found to be reliable and should be used in complement of the first part of the AEPf which assess the prevalence of inappropriate days. It might help to detect dysfunctions within or outside the hospital and thus be used for evaluation or planning of health care.

Adult↗
PubMed2001

How efficacious and safe is short-acting methylphenidate for the treatment of attention-deficit disorder in children and adolescents? A meta-analysis.

BACKGROUND: Numerous small clinical trials have been carried out to study the behaviourally defined efficacy and safety of short-acting methylphenidate compared with placebo for attention-deficit disorder (ADD) in individuals aged 18 years and less. However, no meta-analyses that carefully examined these questions have been done. We reviewed the behavioural evidence from all the randomized controlled trials that compared methylphenidate and placebo, and completed a meta-analysis. METHODS: We searched several electronic sources for articles published between 1981 and 1999: MEDLINE, EMBASE, PsychINFO, ERIC, CINAHL, HEALTHSTAR, Biological Abstracts, Current Contents and Dissertation Abstracts. The Cochrane Library Trials Registry and Current Controlled Trials were also consulted. A study was considered eligible for inclusion if it entailed the following: a placebo-controlled randomized trial that involved short-acting methylphenidate and participants aged 18 years or less at the start of the trial who had received any primary diagnosis of ADD that was made in a systematic and reproducible way. RESULTS: We included 62 randomized trials that involved a total of 2897 participants with a primary diagnosis of ADD (e.g., with or without hyperactivity). The median age of trial participants was 8.7 years, and the median "percent male" composition of trials was 88.1%. Most studies used a crossover design. Using the scores from 2 separate indices, this collection of trials exhibited low quality. Interventions lasted, on average, 3 weeks, with no trial lasting longer than 28 weeks. Each primary outcome (hyperactivity index) demonstrated a significant effect of methylphenidate (effect size reported by teacher 0.78, 95% confidence interval [CI] 0.64-0.91; effect size reported by parent 0.54, 95% CI 0.40-0.67). However, these apparent beneficial effects are tempered by a strong indication of publication bias and the lack of robustness of the findings, especially those involving core ADD features. Methylphenidate also has an adverse event profile that requires consideration. For example, clinicians only need to treat 4 children to identify an episode of decreased appetite. INTERPRETATION: Short-acting methylphenidate has a statistically significant clinical effect in the short-term treatment of individuals with a diagnosis of ADD aged 18 years and less. However, the extension of this placebo-controlled effect beyond 4 weeks of treatment has not been demonstrated. Exact knowledge of the extent and definition of the short-term behavioural usefulness of methylphenidate is questioned.

Adolescent↗
PubMed2002

Intentional use of the Hawthorne effect to improve oral hygiene compliance in orthodontic patients.

The purpose of this study was to evaluate whether the home care of noncompliant adolescent orthodontic patients with "poor" oral hygiene could be improved through the use of a deception strategy designed to intentionally induce the Hawthorne effect. This effect is often cited as being responsible for oral health improvements of control groups that receive placebo treatments. It is thought that participating in and fulfilling the requirements of a study alters subjects' behavior, thereby contributing to the improvement. Forty patients with histories of poor oral hygiene were assigned, in a quasi-random fashion, to two groups. Experimental subjects (n = 20) were presented with a situation that simulated participation in an experiment. These included the use of a consent form; distribution of tubes of toothpaste labeled "experimental"; instructions to brush twice a day for two minutes using a timer; and a request to return unused toothpaste. Control subjects (n = 20) had no knowledge of study participation. Tooth surface area covered with plaque was used as a proxy measure of home care behavior. It was measured at baseline, three months, and six months. Mean percentages of tooth surface covered with plaque for the experimental and control groups were 71 (+/- 11.52) and 74 (+/- 11.46) at baseline; 54 (+/- 13.79) and 78 (+/- 12.18) at three months; and 52 (+/- 13.04) and 79 (+/- 10.76) at six months. No statistically significant difference (p > .05) was obtained between groups at baseline. Statistically significant differences (p < .05) were found between groups at three and six months. Significant differences (p < .05) were also found only for the experimental subjects between baseline and each of the two subsequent observation periods. The efficiency and potential effectiveness of this strategy suggest that additional research be conducted to assess oral health improvements and possible applications to the private practice setting.

Adolescent↗