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PubMed2004

Block design allowed for control of the Hawthorne effect in a randomized controlled trial of test ordering.

BACKGROUND AND OBJECTIVE: To evaluate the value of balanced incomplete block designs in quality improvement research, and their capacity to control for the Hawthorne effect. METHODS: General practitioners teams were randomized into three arms and received an intervention on test ordering, relating to tests for two groups of clinical problems (A tests and B tests). In the two trials within the block design, we tried to control for the Hawthorne effect by comparing the complete intervention in both arms on either the A (arm I) or B tests (arm II); the arms acted as blind controls for each other. In the classical trial, the complete intervention on B tests (arm II) was compared with a control arm without any intervention on B tests (arm III). RESULTS: The trials with the block design yielded statistically significant changes in the numbers of A tests ordered (P=.013), but not in the numbers of B tests ordered (P=.29). In the classical design, the complete intervention reached a marginally significant change in the B tests (P=.068). The Hawthorne effect was the same for both arms of the block design. In the classical design, the effect could to some extent be attributed to the Hawthorne effect. CONCLUSION: Our block design allowed us to control for the Hawthorne effect. Suitable use of block designs may further our knowledge of nonspecific effects in quality improvement research.

Diagnostic Tests, Routine↗
PubMed2004

Genetic predisposition to heart failure.

This review describes the numerous and complex molecular systems that are either known players or candidates in heart failure(HF). All systems whose genetic background has been investigated to date in HF are listed and discussed. Discussion also includes functional notes and known genetic polymorphisms already investigated in HF or candidates that have not yet been investigated. Despite substantial research on HF, relatively few coordinated studies have been conducted that assign precise risk to specific genetic polymorphisms. Identification of risk associated with genetic variations and subsequent translation of genetic knowledge into clinical practice will likely progress only in cases of large coordinated studies based on identical standards. The potential result will be a more accurate definition of HF identified as an evolving complex of cardiovascular diseases.

Adenosine Monophosphate↗
PubMed2006

The effect of education on hypothetical and actual oxygen administration decisions.

AIM: This study examined the effect of an education intervention on emergency nurses' decisions related to oxygen administration. METHOD: A controlled pre-test/post-test quasi-experimental design was used. The intervention was a written self directed learning package. Outcome measures were (i) factual knowledge measured using parallel form multiple choice questions (MCQs) and (ii) clinical decisions measured using parallel form MCQs, parallel form patient scenarios and clinical practice observation. RESULTS: Eighty-eight nurses from 4 Melbourne EDs participated in the study (control group: n=37 and experimental group: n=51). Subgroups of nurses from the experimental group also participated in the patient scenarios (n=20) and clinical practice observation (n=10). Emergency nurses' knowledge increased as a function of education. Both patient scenario data and clinical practice observation showed decreased selection of nasal cannulae, increased selection of air entrainment masks and a trend towards selection of higher oxygen flow rates following education. CONCLUSIONS: Evaluation of educational interventions in nursing should focus on identifying strategies that enhance learning in a clinical environment, are valid in terms of the clinical context and culture in which they are being used and most importantly, produce sustained improvements in actual clinical practice.

Attitude of Health Personnel↗
PubMed2006

Effective weight loss for overweight children: a meta-analysis of intervention studies.

Childhood overweight has increased in the United States. Success of weight-loss programs has been limited (Barlow, S.E., & Dietz, W.H. (1998). Obesity evaluation and treatment: Expert committee recomendations. Pediatrics, 102, e29.). The purpose of this investigation was to systematically examine the effectiveness of weight-loss interventions for children. For this meta-analysis, seven weight-loss intervention studies were coded and quality index scores calculated. The interventions had a significant positive effect on weight-loss average d = 0.95, with a 95% confidence interval of 0.79 to 1.11. Limited interventional studies with effective long-term maintenance of weight loss in children are available in the literature. However, there are effective methods for weight loss in children.

Adolescent↗
PubMed2005

The healthy migrant theory: variations in pregnancy outcomes among US-born migrants.

Various studies have observed that infants born to foreign-born women have better birth outcomes (lower rates of preterm, low birth weight, and infant mortality) than those delivered to US-born women. While much attention has been given to the "healthy migrant effect" as an explanation for these positive outcomes, this theory has not been examined in an internally migrant population. The purpose of this study is to examine the relationship between maternal mobility history and birth outcomes among infants born to US resident mothers of Mexican origin. The study used 1995-1999 National Center for Health Statistics (NCHS) live birth/infant death cohort files of singleton infants delivered in the US to white women of Mexican origin (n = 2,446,253). Maternal mobility history (MMH), which refers to the relationship between the maternal place of birth and the state of residence at delivery, was categorized into the four following groups: (a) foreign-born-place of birth outside the US and delivery in the US; (b) outside-region-place of birth in one US region and delivery in another US region; (c) within-region-place of birth in one US region and delivery in a different state in the same US region; and (d) within-state-place of birth and delivery in the same US state. Consistently, there is evidence to support the healthy migrant effect in an internally migrant population. Unique to this study are the findings that infants born to mothers with outside-region MMH had a lower risk of low birth weight (LBW) and small-for-gestational age (SGA) compared to those who did not move. Overall, this study provides evidence that the healthy migrant effect and its relationship to birth outcomes can be applied to an internally migrant population.

Adult↗
PubMed2006

Outpatient process quality evaluation and the Hawthorne Effect.

We examine the evidence that the behavior of clinicians is impacted by the fact that they are being observed by a research team. Data on the quality of care provided by clinicians in Arusha region of Tanzania show a marked fall in quality over time as new patients are consulted. By conducting detailed interviews with patients who consulted both before and after our research team arrived we are able to show strong evidence of the Hawthorne effect. Patient-reported quality is steady before we arrive, rises significantly (by 13 percentage points) at the moment we arrive and then falls steadily thereafter. We show that quality after we arrive begins to look similar to quality before we arrived between the 10th and 15th consultations. Implications for quality measurement and policy are discussed.

Ambulatory Care↗
PubMed2006

Beneficial non-targeted effects of BCG--ethical implications for the coming introduction of new TB vaccines.

Non-targeted effect of BCG: Several recent studies suggest that BCG has beneficial non-targeted effects on general child survival in low-income countries. Studies of the effect of BCG on morbidity in humans are scarce; some found a positive effect of BCG and others show no effect. Non-targeted effects of vaccines-possible bias and confounding: The major argument against comparing vaccinated and unvaccinated groups is that there is a beneficial social selection bias for vaccinated children-the "Healthy vaccinee effect". However, controlling for various social and health-related background factors in the survival analyses had no effect on the estimates, making this source of bias less likely. A more powerful argument that the findings are not due to the healthy vaccinee effect is that differential non-targeted effects of other vaccines have been observed; diphteria-tetanus-pertussiss vaccination has marked negative effects on child survival, whereas measles vaccine has a positive effect in several studies. Several studies have shown better survival for children reacting to their BCG vaccination with a BCG scar or tuberculin skin test reaction (TST). It could be argued that the reacting children were immunologically stronger and therefore more likely to survive-the "Healthy reactor effect". However, recent findings show that a BCG scar and a TST reaction depend to a large extent on the vaccination technique. Hence, the BCG responses may reflect a true vaccine effect and not merely the health status of the children. Since HIV-1 has been shown to suppress both TST and BCG scar reaction in response to BCG, it is an obvious contributor to the healthy reactor effect, but excluding deaths of children with HIV-1 infection from analysis did not affect the beneficial effect of having a positive TST. Excluding children exposed to tuberculosis (TB) in the household did not affect the estimates either. Furthermore, there are strong sex-differential effects of BCG in both mortality and morbidity data, BCG being more beneficial for girls. These observations cannot consistently be explained by the healthy vaccinee or healthy reactor effects. Ethical implications: For future TB-vaccine studies, these findings imply that: These recommendations might be considered to delay or to be a too large obstacle for the development and trials of new TB vaccines. However, most of the non-targeted beneficial effects of BCG have been observed in children below 2 years of age, which is not a long follow-up time in a TB-vaccine trial. Furthermore, considering the difficulty in setting the TB diagnose in children and the lack of reliable TB-protection markers, it does not seem unreasonable to argue for monitoring of general morbidity and survival in future TB-vaccine trials.

BCG Vaccine↗
PubMed1998

Impairment level sumscore in reflex sympathetic dystrophy of one upper extremity.

OBJECTIVES: To construct a set of instruments to measure the level of impairment in reflex sympathetic dystrophy (RSD), to convert the scores for each instrument into one score and to derive a compounded impairment level sumscore (ISS), and to evaluate reliability, validity, and responsiveness of the ISS. DATA SOURCES AND EXTRACTION: Literature search in Medline (1985 to 1995), non-Medline journals, and references from these reports for measurement parameters and suitable, reliable, responsive, and validated instruments. DATA SYNTHESIS: Four measurement parameters (pain, active range of motion, temperature, and volume) and five measurement instruments were chosen to construct the ISS. All outcomes were converted into one score, resulting in an addable score. RESULTS: Forty-five patients with RSD of one upper extremity were evaluated. As expected for this heterogeneous index, the internal consistency of the ISS was poor to moderate. The ISS seemed to have content and concurrent validity. The responsiveness of the ISS was adequate. CONCLUSIONS: A multicomponent test was constructed to map alterations in the level of impairment in RSD patients. Each of the parameter scores could be translated into a uniform score. Adding the scores yielded the ISS.

Arm↗
PubMed1998

Speed dependence of crutch force and oxygen uptake: implications for design of comparative trials on orthoses for people with paraplegia.

OBJECTIVE: To determine speed dependence of crutch force and oxygen uptake, and to discuss the implications of differences in self-selected walking speed between orthoses in a comparative trial. DESIGN: Cross-sectional comparison. SETTING: Treadmill experiments and gait laboratory experiments were performed at five and three different imposed walking speeds, respectively. PATIENTS: Five paraplegic subjects with lesions between T9 and T12 were included. All subjects had experience with ambulation using the advanced reciprocating gait orthosis (ARGO) as well as walking on a treadmill. MAIN OUTCOME MEASURES: Crutch force time integral (CFTI), crutch peak force on stance and swing side (CPFstance and CPFswing), oxygen uptake (VO2), oxygen cost (EO2). RESULTS: VO2, EO2, and CFTI were strongly dependent on walking speed. CPFstance and CPFswing were less dependent. However, depending on the clinically relevant difference that should be detected in a comparative trial, the peak forces can still be confounded by walking speed. CONCLUSION: CFTI, CPFswing, VO2, and EO2 should be adjusted for walking speed if differences in walking speed between orthoses are found, but this correction is relevant only if there is no effect modification. Such modification (different slopes between orthoses) cannot be excluded for the studied outcome measures. In addition, because determination of effect modification is difficult in small studies, standardization of walking speed, by means of a three-point design, is recommended.

Adult↗
PubMed1999

Anterior ankle-foot orthosis effects on postural stability in hemiplegic patients.

OBJECTIVES: To evaluate the effects of an anterior ankle-foot orthosis (AFO) on static and dynamic postural stability in hemiplegic patients. DESIGN: A cross-sectional assessment of hemiplegic subjects with and without an AFO. SETTING: Outpatient department of a rehabilitation hospital. PATIENTS: A convenience sample of 24 subjects who had been prescribed an anterior AFO. OUTCOME MEASURES: Postural sway index and postural symmetry (body weight distribution through the affected leg) when standing were measured as static postural stability. Maximal balance range in anterior-posterior and lateral directions and the affected leg's weight bearing after weight shift to affected side were measured as dynamic postural stability. RESULTS: When wearing the anterior AFO, there was no significant difference and small effect size (r<0.3) in postural sway index (p = .35), postural symmetry (p = .21), and maximal balance range in anterior-posterior direction (p = .46). There was a significant improvement and large effect size (r>0.5) in lateral weight shifting (p<.01) and weight bearing through the affected leg after weight shifted to the affected side (p<.01). CONCLUSIONS: The significant effects of the anterior AFO in long-term hemiplegic patients were on lateral weight shifting and weight bearing through affected leg after weight shifted to the affected side. Postural sway, postural symmetry, and anterior-posterior weight shifting were not significantly affected.

Adult↗
PubMed1997

Effect of cognitive-behavioural training on job-finding among long-term unemployed people.

BACKGROUND: The principles of cognitive-behavioural therapy (CBT) have been applied successfully through individual psychotherapy to several psychiatric disorders. We adapted these principles to create a group--training programme for a non-psychiatric group-long-term (> 12 months) unemployed people. The aim was to investigate the effects of the programme on measures of mental health, job-seeking, and job-finding. METHODS: 289 volunteers (of standard occupational classification professional groups) were randomly assigned to a CBT or control programme, matched for all variables other than specific content, that emphasised social support. 244 (134 CBT, 110 control) people started the programmes and 199 (109 CBT, 90 control) completed the whole 7 weeks of weekly 3 h sessions (including three CBT, seven control participants who withdrew because they obtained employment or full-time training). Questionnaires completed before training, on completion, and 3-4 months later (follow-up data available for 94 CBT, 89 control) assessed mental health, job-seeking activities, and success in job-finding. Analyses were based on those who completed the programmes. Participants were not aware that two interventions were being used. Investigators were aware of group allocation, but were accompanied in all programmes by co-trainers who were non-investigators. FINDINGS: Before training, 80 (59%) CBT-group participants and 59 (54%) controls scored 5 or more on the general health questionnaire (GHQ; taken to define psychiatric caseness). After training, 29 (21%) and 25 (23%), respectively, scored 5 or more (p < 0.001 for both decreases). Improvements in mean scores with training on the GHQ (between-group difference 3.91, p = 0.05) and in other measures of mental health were significantly greater in the CBT group than in the control group. There were no significant differences between the groups in job-seeking activity during or after training, but significantly more of the CBT group than of the control group had been successful in finding full-time work (38 [34%] vs 13 [13%], p < 0.001), by 4 months after completion of training. INTERPRETATION: These results suggest that group CBT training can improve mental health and produce tangible benefits in job-finding. Application of CBT among the unemployed is likely to benefit both individuals and society in general.

Adult↗
PubMed2001

Increased catecholamine levels in urine in subjects exposed to road traffic noise: the role of stress hormones in noise research.

The nocturnal excretion of catecholamines in urine was studied in 30-45-year-old women whose bedroom and/or living room were facing streets of varying traffic volume. The traffic volume of the streets was used as an indicator of noise exposure; adrenaline and noradrenaline concentrations were assessed as indicators of the outcome of the physiological stress. Significant associations between traffic volume and noradrenaline concentrations in urine were found with regard to the exposure of the bedroom (not the living room), indicating a higher chronic physiological arousal in noise-exposed subjects as compared to less exposed. Subjective measures of disturbance due to traffic noise were positively correlated with the noradrenaline level. However, this was only found in subjects where closing the window could not reduce the perceived disturbance, which points to the effectiveness of individual coping mechanisms. Stress hormones are useful indicators to study associations, mechanisms, and interactions between noise, health outcomes, and effect modifiers in epidemiological noise research.

Adaptation, Psychological↗
PubMed2001

Evidence for genetic heterogeneity within eight glaucoma families, with the GLC1A Gln368STOP mutation being an important phenotypic modifier.

OBJECTIVE: To investigate the phenotype and age-related penetrance of primary open-angle glaucoma (POAG) in Australian families with the most common Myocilin mutation (Gln368STOP). DESIGN: Cross-sectional genetic study. PARTICIPANTS: Eight pedigrees carrying the Gln368STOP mutation were ascertained from 1730 consecutive cases of POAG in the Glaucoma Inheritance Study in Tasmania. METHODS: Index cases and available family members were examined for signs of glaucoma, and the presence of the GLC1A Gln368STOP mutation was ascertained by single-strand conformation polymorphism analysis and subsequent direct sequencing. RESULTS: From the eight pedigrees, 29 Gln368STOP mutation-carrying individuals with either ocular hypertension (OHT) or POAG were found, with a mean age at diagnosis of 52.4 +/- 12.9 years and a mean peak intraocular pressure (IOP) of 28.4 +/- 4.7 mmHg. A further 11 mutation carriers older than 40 years have been studied, who as yet show no signs of OHT or POAG. Within the 8 pedigrees, a further 31 individuals with OHT or POAG were identified who did not carry the Gln368STOP mutation. For these individuals the mean age at diagnosis was higher (62.3 +/- 13.7 years, P < 0.01), and the mean peak IOP was lower (25.4 +/- 6.4 mmHg, P = 0.01). For Gln368STOP carriers, age-related penetrance for OHT or POAG was 72% at age 40 years and 82% at age 65 years. A positive family history of POAG was present in all index cases. Five of the eight pedigrees had a positive family history on both maternal and paternal sides. Seven of the eight pedigrees had one or more individuals with POAG who did not carry the mutation. Eight of the 29 Gln368STOP carriers with OHT or POAG had undergone trabeculectomy. CONCLUSIONS: The GLC1A Gln368STOP mutation is associated with POAG, which in the pedigrees studied is of a younger age of onset and higher peak IOP than non-mutation glaucoma cases. In addition, Gln368STOP mutation glaucoma cases were more likely to have undergone glaucoma drainage surgery. We have not observed simple autosomal dominant inheritance patterns for POAG in these pedigrees. Other factors, as yet uncharacterized, are involved in expression of the POAG phenotype in Gln368STOP pedigrees.

Adult↗
PubMed2001

Meta-analyses of prospective studies on coronary heart disease, type A personality, and hostility.

BACKGROUND: Several large-scale prospective studies have failed to find an association between Type A personality (TAP) or hostility and coronary heart disease (CHD). The existing meta-analyses on this topic have several shortcomings, such as a selective search of the literature, the failed use of effect sizes, and methodological flaws. METHODS: The present meta-analyses cover all prospective studies until the end of 1998. The correlation coefficient r is used as effect size to yield information on the population effect size R and variance. Several analyses have been carried out to stratify for disease endpoints, samples (healthy population, CHD patients), and methods used to determine TAP or hostility. RESULTS: The population effect size (weighted average of all correlation coefficients) for TAP and CHD is R=0.003 (n=74,326, P=0.213), and for hostility and CHD R=0.022 (n=15,038, P=0.003). CONCLUSIONS: The population effect size for TAP and CHD is not significant. Hostility yields a significant association with CHD; however, the effect size is so low that it has as yet no practical meaning for prediction and prevention.

Coronary Disease↗