Comparison Of Mean Differences Research Articles

Verbessert das Resident Assessment Instrument die ambulante Pflege? - Ergebnisse einer bundesweiten Studie

Effective and efficient instruments for care planning and controlling are required to optimise the nursing process and improve outcome quality despite of various lacks of quality and precarious circumstances. A cluster randomised controlled trial was conducted to assess whether the implementation of the Resident Assessment Instrument (RAI) into home care service providers can help to improve or stabilise functional abilities (ADL, IADL) and cognitive skills (MMST), improve quality of life (EQ-5D), reduce institutionalisation and thereby increase outcome quality. A comparison of mean differences between the treatment and control group showed no significant effects. Although the multilevel regression results show that clients in the treatment group fared better in terms of ADL and IADL (smaller decline) and were less likely to move to nursing homes and be hospitalised, none of these effects are significant. The lack of significance might be due to the fact that RAI was not fully implemented and even the partial implementation lasted much longer than expected. Moreover, the number of clients included in the study was smaller than originally planned.

Effects of the Resident Assessment Instrument in home care settings

Deficits in quality, a lack of professional process management and, most importantly, neglect of outcome quality are criticized in long-term care. A cluster randomized, controlled trial was conducted to assess whether the Resident Assessment Instrument (RAI) can help to improve or stabilize functional abilities (ADL, IADL) and cognitive skills (MMST), improve quality of life (EQ-5D), and reduce institutionalization, thereby, increasing outcome quality. A total of 69 home care services throughout Germany were included and randomized. The treatment group (n = 36) received training in RAI and was supported by the research team during the study (13 months). Comparison of mean differences between the treatment and control groups (n = 33) showed no significant effect. Although the multilevel regression results show that clients in the treatment group fared better in terms of ADLs and IADLs (smaller decline) and were less likely to move to nursing homes and be hospitalized, none of these effects is significant. The lack of significance might result from the small number of clients included in the study. Moreover, RAI was not fully implemented and even partial implementation required more time than expected.

Is There a Risk of Bleeding Associated with Standardized Ginkgo bilobaExtract Therapy? A Systematic Review and Meta‐analysis

To determine the effect of standardized Ginkgo biloba leaf extracts (GBE) on outcome parameters of hemostasis associated with risk of bleeding. Meta-analysis of 18 randomized controlled trials. A total of 1985 adults were enrolled to receive either GBE or placebo; 87% were patients with dementia, peripheral artery disease, or diabetes mellitus; 13% were healthy volunteers. The MEDLINE, EMBASE, Cochrane Library, and SciSearch databases were searched from inception through 2009. The following outcome parameters of hemostasis were assessed: blood flow, blood viscosity, adenosine 5'-diphosphate (ADP)-induced platelet aggregation, fibrinogen concentration, activated partial thromboplastin time (aPTT), and prothrombin time (PT). Reference parameter values were taken into account when assessing clinical relevance of statistically significant treatment effects. The quality and risk of bias of each study were evaluated by using the Jadad score and Cochrane Collaboration tool, respectively. According to the continuous data, the following statistical methods were used: weighted mean difference (WMD), standardized mean difference (SMD), and generic inverse variance (GIV), with 95% confidence intervals (CIs). Random-effects models of effects on baseline change or mean difference showed a positive effect of GBE on blood perfusion, as shown by a significant reduction in blood viscosity (WMD -1.03 mPa•sec, 95% CI -1.29 to -0.78 mPa•sec), but no evidence of any significant effect on ADP-induced platelet aggregation (WMD -0.35%, 95% CI -15.16-14.46%), fibrinogen concentration (GIV -2.45 mg/dl, 95% CI -11.59-6.70 mg/dl), aPTT (GIV -0.42 sec, 95% CI -0.97-0.12 sec), and PT (SMD 0.00, 95% CI -0.09-0.09). Subgroup analyses revealed a statistically significant reduction in aPTT for subgroups receiving high-dose GBE of 240 mg/day or more (GIV -0.47 sec, 95% CI -0.88 to -0.05 sec) and for studies including only patients, not healthy volunteers (GIV -0.61 sec, 95% CI -0.95 to -0.27 sec); however, both findings were not clinically relevant. Based on meta-analysis of hemostasis outcomes, comparison of mean difference or baseline change between treatment and placebo groups did not indicate a higher bleeding risk associated with standardized GBE. This finding ultimately contributes to an informed evaluation of GBE use, including patient self-medication.

Effects of music intervention on physiological stress response and anxiety level of mechanically ventilated patients in China: a randomised controlled trial

To examine the effects of music intervention on the physiological stress response and the anxiety level among mechanically ventilated patients in intensive care unit. Despite the fact that previous studies have found music interventions to be effective in stress and anxiety reduction, effects of music on the Chinese population are inconclusive and warranted systematic study to evaluate its effect fully for a different Asian culture. A randomised placebo-controlled trial. A total of 137 patients receiving mechanical ventilation were randomly assigned to either music listening group, headphone group or control group. Outcome measures included the Chinese version of Spielberger State-Trait Anxiety Scale and physiological parameters (heart rate, respiratory rate, saturation of oxygen and blood pressure). Comparison of mean differences (pretest score-posttest score) showed significant differences in heart rate, respiratory rate, systolic blood pressure and diastolic blood pressure as well as the Chinese version of Spielberger State-Trait Anxiety Scale, but not in SaO(2) among the three groups (ranging from p < 0.001 to p = 0.007), of which greater mean differences were found in music listening group. A significant reduction in physiological stress response (heart rate and respiratory rate) over time was found in music listening group (p < 0.001 for both variables) and a significant increase in heart rate and respiratory rate over time in control group (p < 0.001 and p = 0.032), with no significant change over time in headphone group. Within group pretest-posttest comparison of the Chinese version of Spielberger State-Trait Anxiety Scale demonstrated a significant reduction in anxiety for the music listening group (p < 0.001) and headphone group (p < 0.001) but not the control group. Our findings confirm that short-term therapeutic effects of music listening results in substantial reduction in physiological stress responses arising from anxiety in mechanically ventilated patients. Music as a non-pharmacological nursing intervention can be used as complementary adjunct in the care of patients with low-energy states who tire easily, such as those requiring mechanical ventilator support.

Exploring Sex Differences in Worry with A Cognitive Vulnerability Model

A multivariate model was developed to examine the relative contributions of mastery, stress, interpretive bias, and coping to sex differences in worry. Rumination was incorporated as a second outcome variable to test the specificity of these associations. Participants included two samples of undergraduates totaling 302 men and 379 women. A path analysis of the full sample demonstrated good overall fit and revealed that low mastery, high stress, and high interpretive bias predicted increases in both worry and rumination. There proved to be no interactive effect of sex with the model. Comparisons of mean differences indicated that women reported significantly lower mastery and significantly higher stress, worry, and rumination than men. Results suggest similar processes confer risk for worry and rumination in men and women; however, lower levels of mastery and higher levels of stress in women may contribute to the female preponderance of anxiety and depression.

Automated versus manual blood pressure measurement: A randomized crossover trial

This study evaluated the accuracy and reliability of the Dinamap 8100 automated blood pressure machine against three internationally recognized criteria. Systolic and diastolic blood pressures were taken concurrently by two nurses using the automated machine and a manual sphygmomanometer. Results demonstrated agreement between automated and manual readings on one set of criteria for both systolic and diastolic pressures, and support for systolic readings only on one other criterion. Comparison of mean differences between automated and manual measures showed the automated machine consistently under-read both systolic and diastolic blood pressures. The conclusion from this study was that the Dinamap 8100 machine can be used with some degree of confidence to assess systolic blood pressures in a general population of adult hospital inpatients, but with caution when taking diastolic readings.

Testing for Between-Group Differences in Within-Group Interrater Agreement

Users of rwg may find situations where they want to compare the levels of within-group agreement across two or more groups. F tests are presented that compare two values of rwg, rwg(J), or r*wg(J), and recommendations are made for comparing pairwise group values for three or more groups with a control for alpha inflation. More robust and flexible methods based on O'Brien's test are then recommended when sufficient raw data are available. The meaning of findings that agreement statistics are either the same or different across groups is discussed in light of simultaneous comparisons of mean differences. Examples are shown to demonstrate the robust methods using employee responses to questions regarding climate perceptions of organizational support for employee development activities. Other scenarios where the F test may prove useful are discussed, and directions for future research are provided.

Validation of a method for identifying nursing home admissions using administrative claims

BackgroundCurrently there is no standard algorithm to identify whether a subject is residing in a nursing home from administrative claims. Our objective was to develop and validate an algorithm that identifies nursing home admissions at the resident-month level using the MarketScan Medicare Supplemental and Coordination of Benefit (COB) database.MethodsThe computer algorithms for identifying nursing home admissions were created by using provider type, place of service, and procedure codes from the 2000 – 2002 MarketScan Medicare COB database. After the algorithms were reviewed and refined, they were compared with a detailed claims review by an expert reviewer. A random sample of 150 subjects from the claims was selected and used for the validity analysis of the algorithms. Contingency table analysis, comparison of mean differences, correlations, and t-test analyses were performed. Percentage agreement, sensitivity, specificity, and Kappa statistics were analyzed.ResultsThe computer algorithm showed strong agreement with the expert review (99.9%) for identification of the first month of nursing home residence, with high sensitivity (96.7%), specificity (100%) and a Kappa statistic of 0.97. Weighted Pearson correlation coefficient between the algorithm and the expert review was 0.97 (p < 0.0001).ConclusionA reliable algorithm indicating evidence of nursing home admission was developed and validated from administrative claims data. Our algorithm can be a useful tool to identify patient transitions from and to nursing homes, as well as to screen and monitor for factors associated with nursing home admission and nursing home discharge.

Importance of Effect Sizes for the Accumulation of Knowledge

Importance of Effect Sizes for the Accumulation of Knowledge

Association of COMT Val158Met Genotype With Executive Functioning Following Traumatic Brain Injury

Catechol-O-methyltransferase (COMT) is thought to functionally modulate dopamine neurons, thus likely influencing frontal-executive functioning. High enzyme activity (COMT Val) and low enzyme activity (COMT Met) are functional polymorphisms resulting from a G to A transition in exon 4 (codon 158) of the human COMT gene. Decreased cortical dopamine should result in poorer executive functioning. Therefore, the authors hypothesized that individuals with traumatic brain injury (TBI) and the low enzyme activity polymorphism would perform better on tests of executive functioning than individuals with the high enzyme activity polymorphism. One hundred thirteen individuals referred to the Defense and Veterans Brain Injury Center underwent a comprehensive TBI evaluation and were genotyped for the COMT polymorphism. Comparison of mean differences among the COMT genotype groups for several measures of aspects of executive functioning was conducted using analysis of variance (ANOVA) with adjustment for multiple comparisons. Homozygotes for the higher activity allele made more perseverative responses on the Wisconsin Card Sorting Test, while homozygotes for the lower activity allele had the least number of perseverative responses. While it cannot be determined whether TBI influenced the association of COMT Val158Met to executive functioning, these data extend the known relationship of genotype to executive performance seen in healthy comparison subjects and individuals with schizophrenia to individuals with TBI.

Association of COMT Val158Met Genotype With Executive Functioning Following Traumatic Brain Injury

Catechol-O-methyltransferase (COMT) is thought to functionally modulate dopamine neurons, thus likely influencing frontal-executive functioning. High enzyme activity (COMT Val) and low enzyme activity (COMT Met) are functional polymorphisms resulting from a G to A transition in exon 4 (codon 158) of the human COMT gene. Decreased cortical dopamine should result in poorer executive functioning. Therefore, the authors hypothesized that individuals with traumatic brain injury (TBI) and the low enzyme activity polymorphism would perform better on tests of executive functioning than individuals with the high enzyme activity polymorphism. One hundred thirteen individuals referred to the Defense and Veterans Brain Injury Center underwent a comprehensive TBI evaluation and were genotyped for the COMT polymorphism. Comparison of mean differences among the COMT genotype groups for several measures of aspects of executive functioning was conducted using analysis of variance (ANOVA) with adjustment for multiple comparisons. Homozygotes for the higher activity allele made more perseverative responses on the Wisconsin Card Sorting Test, while homozygotes for the lower activity allele had the least number of perseverative responses. While it cannot be determined whether TBI influenced the association of COMT Val158Met to executive functioning, these data extend the known relationship of genotype to executive performance seen in healthy comparison subjects and individuals with schizophrenia to individuals with TBI.

Quality of Life after Adenotonsillectomy for SDB in Children

To evaluate the relationship between quality of life and the relative severity of sleep-disordered breathing (SDB) and to compare changes in quality of life after adenotonsillectomy in children with similar demographics but with either obstructive sleep apnea syndrome (OSAS) or with milder forms of SDB. All study participants underwent polysomnography to document the severity of SDB. The effectiveness of adenotonsillectomy for the relief of SDB was evaluated by using the OSA-18 quality of life survey (OSA-18). Preoperative and postoperative OSA-18 scores for each group of children (OSAS and mild SDB) were compared by using a repeated measures ANOVA. Changes between the 2 groups were compared by using an analysis of covariance with the preoperative score as a covariate. The study population included 61 children, 43 with OSAS and 18 with mild SDB. The demographics in the 2 groups were similar. The mean apnea-hypopnea index for children with OSAS was 21 (range, 5-46), and for children with mild SDB, it was 3 (range 0-4.9). The total OSA-18 score and the scores for all domains showed significant improvement after surgery for both groups of children (P < .001). A comparison of mean difference in total and domain scores for the 2 groups of children was not significant. Preoperative values for the OSA-18 total and domain scores are high in children with either OSAS or mild SDB. Both groups of children show a dramatic improvement in quality of life after adenotonsillectomy and the degree of improvement is similar. Fortunately, surgical therapy with adenotonsillectomy is associated with marked improvement in quality of life for children with either OSAS or mild SDB.

Early attention and negative emotionality predict later cognitive and behavioural function

Negative emotionality and poor attention may combine or interact as risk factors in development. Negative emotionality is considered a challenge for self-regulation, whereas good attention is a potential means of self-regulation. In the current study, composites of 1- and 2-year maternal ratings of negative emotionality and global ratings of observed attentiveness were predictors for 3.5-year cognitive and behavioural outcome for 75 children. Results of variable-based regression analyses indicated that early negativity and attentiveness predicted IQ and scores on a hyperactivity index; only negativity predicted a global measure of behaviour problems. Results of person-based analyses for groups formed by median splits on negativity and attention suggested that the More Negative/Less Attentive group had significantly poorer outcome than the other three groups combined (those with one or none of the two risk factors). Comparisons of mean differences also suggested a protective effect of greater attentiveness for more negative as opposed to less negative children for all outcomes. The results extend prior work in providing longitudinal data over the first 3 years and including both cognitive and behavioural outcomes.

Variability orders and mean differences

Several well-known stochastic orderings are defined in terms of iterated integrals of distribution or survival functions. In this note we will provide necessary conditions for some variability orderings of the above type. These conditions will be based on the comparison of mean differences, which will be written by using the iterated integrals of survival and distribution functions. An interesting by-product of this idea is a curious formula for the variance. A bivariate version of the above results will be provided, as well.

Motivational Distortion of the 16PF by Welfare Recipients

The effectiveness of the Sixteen Personality Factor (16PF) motivational distortion correction procedures was investigated with a sample of 212 welfare recipients who completed the 16PF while participating in a mandatory welfare-to-work program. A multiple regression analysis showed that the motivational distortion (MD) score was significantly related to most of the preselected personality factors. The regression analysts also revealed that primary E (Dominance) was associated with MD, although the manual does not require MD adjustments for this factor. Based on comparisons of mean differences at the various MD correction levels, findings indicated general support for the MD correction procedures described in the manual; however, the magnitude of the correction procedures should be used cautiously as this may overcorrect for MD on some of the 16PF primaries. The relevance of the findings also are discussed in terms of evidence for Cattell's (1968, 1973, 1986) trait-view theory as it applies to response distortions.

Calculation of Standardized, Noncentered Factor Scores: An Alternative to Conventional Factor Scores

Conventional methods for computing factor scores yield factor scores with a mean of zero on each factor. This precludes meaningful comparisons of mean differences across factors. An algorithm for computing scores that are standardized but do not have means of zero is proposed and illustrated.

Prediction of percent body fat in adult males using dual energy x-ray absorptiometry, skinfolds, and hydrostatic weighing

The purpose of this study was to compare the prediction of percent body fat (%FAT) by dual energy x-ray absorptiometry (DXA), skinfolds (SF), and hydrostatic weighing (HW) in adult males. Subjects were 35 adult male Caucasians (mean +/- SD; age: 39.1 +/- 14.0 yr, height: 180.6 +/- 5.3 cm, weight: 81.0 +/- 11.1 kg). %FAT, determined by HW with residual volume determined via O2 dilution, served as the criterion. DXA %FAT was determined by the Norland XR-26 (XR-26) bone densitometer and by the SF equations of Jackson and Pollock (JP) (1978), and Lohman (LOH) (1981). Criterion referenced validation included analyzing mean (+/- SD) %FAT values using a one-way ANOVA for significance, comparison of mean differences (MD), correlations (r), standard error of estimates (SEE), and total errors (TE). Significant differences were found between means of each method. The r (0.91) and SEE (3.0 %FAT) for DXA compare favorably with the established SF methods of JP and LOH for predicting %FAT; however, DXA demonstrated the largest MD (3.9 %FAT) and TE (5.2 %FAT). Regression analysis yields HW = 0.79* DXA + 0.56. The results do not support earlier research that found no significant difference between HW and DXA %FAT in males. The study suggests the density of the fat-free body (DFFB) is not constant, and that the variation in bone mineral content affects the DFFB, which contributes to the differences between DXA and HW %FAT. We recommend further research to identify inconsistencies between manufacturers of DXA equipment in prediction of %FAT in males.

Histamine antagonists in the treatment of acute allergic reactions

We compared the efficacies of cimetidine (an H2-receptor antagonist) and diphenhydramine (an H1-receptor antagonist) alone and in combination for alleviation of symptoms of acute allergic reactions. STUDY DESIGN AND INTERVENTIONS: In this prospective, randomized, double-blind study, patients and examiners assessed the severity of symptoms and signs of acute allergic reactions using a visual-analog scale before treatment and 30 minutes after treatment with 300 mg IV cimetidine and placebo, 50 mg IV diphenhydramine and placebo, or diphenhydramine plus cimetidine. Thirty-nine patients with acute allergic reactions presenting to two emergency departments of teaching hospitals. Of the 35 patients with pruritus, all 12 receiving diphenhydramine placebo had clinically significant relief compared with six of ten (60%) receiving cimetidine plus placebo (P = .03). Twelve of 13 (92%) receiving diphenhydramine plus cimetidine had relief, which was not a significant difference from the single drugs. Comparison of mean differences in pretreatment and post-treatment symptom scores (relief scores) among groups of patients with pruritus detected significantly more relief in the group receiving diphenhydramine plus placebo (80.3 +/- 7.4) than in those receiving cimetidine plus placebo (48.8 +/- 13.4) (P = .022). Of the 33 patients with urticaria, five of 11 (46%) receiving diphenhydramine plus placebo had clinically significant relief compared with eight of ten (80%) receiving cimetidine plus placebo (P = .18). Eleven of 12 patients (92%) receiving diphenhydramine plus cimetidine had relief, which is a significant difference from those receiving diphenhydramine plus placebo (P = .027). Comparison of mean relief scores in patients with urticaria detected significantly more relief in the group receiving diphenhydramine plus cimetidine (55.3 +/- 6.5) than in the group receiving diphenhydramine plus placebo (30.7 +/- 6.1) (P = .006). For treatment of pruritus from acute allergic reactions, diphenhydramine is more effective than cimetidine, and the combination offers no additional benefit. For treatment of acute urticaria, the combination of cimetidine and diphenhydramine is more effective than diphenhydramine alone.

AGE OF ONSET IN SIBLINGS CONCORDANT FOR MULTIPLE SCLEROSIS

We have evaluated genetic and environmental influences in multiple sclerosis (MS) by comparing age of onset in 99 sibling pairs concordant for the disease. We used three methods of analysis: (1) comparison of mean differences in age of onset and year of onset, (2) linear regression of differences in age or year of onset vs difference in ages, and (3) intraclass correlation of age of onset which is also used for monozygotic twins concordant for MS. Comparison of the mean differences in age of onset or year of onset is found to be inappropriate and potentially misleading. No significant results were found in linear regression of the age of onset or year of onset vs differences in ages, although a trend towards onset at the same age is present. However, nontwin siblings show a significant intraclass correlation for age of onset (P less than 0.01) as is seen in genetic disorders. A stronger intraclass correlation in age of onset in concordant monozygotic twins vs concordant sibling pairs further suggests that age of onset is partly under genetic control, assuming common exposure to an environmental agent. The results give little support for common exposure to an environmental trigger in concordant MS sibling pairs. They are consistent with a mixture of random independent exposures and common exposures leading to the development of the disease, with the former predominating.

The combination of ibuprofen and oxycodone/acetaminophen in the management of chronic cancer pain

Thirty subjects with chronic moderate to severe pain who were receiving oxycodone/acetaminophen (oxy/APAP) for analgesia were initially evaluated for at least 7 days for oxy/APAP requirements for pain control. Each subject then received, in a randomized double-blind fashion, either 600 mg ibuprofen or placebo for an additional 7 days while hospitalized. Oxy/APAP usage was recorded daily along with efficacy and toxicity parameters. Overall global evaluations were also recorded on completion of the study. Comparison of mean differences before and after treatment with ibuprofen or placebo indicated a marked decrease in oxy/APAP use with ibuprofen (p less than 0.01) and a slight increase in use in the placebo group. Reduction in oxy/APAP usage occurred within 24 hours and maximized at 5 days. Overall global scores showed a marked preference for the ibuprofen combination over placebo (p less than 0.01). Daily pain intensity (p less than 0.05) and pain relief scores (p less than 0.05) also improved with the addition of ibuprofen. This study indicates that ibuprofen is efficacious in the management of chronic cancer pain, resulting in both enhanced analgesia and a reduction in concomitant narcotic use.