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Methodological Study (methodological + study)

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Medical Sciences	100%

Selected Abstracts

Circadian Variation in QT Dispersion Determined from a 12-Lead Holter Recording: A Methodological Study of an Age- and Sex-Stratified Group of Healthy Subjects

ANNALS OF NONINVASIVE ELECTROCARDIOLOGY, Issue 3 2007
Stig Hansen M.D.
Background: QT dispersion is considered to reflect inhomogeneity of myocardial repolarization. Method: The circadian variation of QT interval dispersion was examined in 95 healthy subjects using 24-hour Holter monitoring. Three different methods of lead selection were applied: all 12 leads (QTdisp 12), only precordial leads (QTdisp 6), and the pair of leads selected at 3 a.m. in which the longest and shortest QT intervals were found in each individual subject (QTdisp 2). Results: A preliminary methodological study including measurements from every minute in 10 subjects revealed no significant circadian variation using mean values of QTdisp 12, QTdisp 6, or QTdisp 2 obtained every hour, every 2, or every 4 hours, except in QTdisp 6, which demonstrated a significant circadian variation (P < 0.01) in 1-hour measurements. Analysis of all 95 subjects using measurements obtained every 4 hours revealed a significant circadian variation in QTdisp 12 and QTdisp 6 (P < 0.0001), whereas no circadian variation was seen in QTdisp 2. A subdivision into 10-year age groups revealed that subjects at age >50 years had a significant circadian variation in QTdisp 12 and QTdisp 6, but not in QTdisp 2. Only in males a significant circadian variation was seen in QTdisp 12 (P < 0.0001), whereas QTdisp 6 demonstrated a circadian variation both in females (P < 0.001) and in males (P < 0.0001). Conclusions: Selection of leads is of crucial importance for repetitive measurements of QT dispersion. Circadian variation was detected in subjects over 50 years of age, when all 12 or only the 6 precordial leads were taken into account. [source]

Power of Tests for a Dichotomous Independent Variable Measured with Error

HEALTH SERVICES RESEARCH, Issue 3 2008
Daniel F. McCaffrey
Objective. To examine the implications for statistical power of using predicted probabilities for a dichotomous independent variable, rather than the actual variable. Data Sources/Study Setting. An application uses 271,479 observations from the 2000 to 2002 CAHPS Medicare Fee-for-Service surveys. Study Design and Data. A methodological study with simulation results and a substantive application to previously collected data. Principle Findings. Researchers often must employ key dichotomous predictors that are unobserved but for which predictions exist. We consider three approaches to such data: the classification estimator (1); the direct substitution estimator (2); the partial information maximum likelihood estimator (3, PIMLE). The efficiency of (1) (its power relative to testing with the true variable) roughly scales with the square of one less the classification error. The efficiency of (2) roughly scales with the R2 for predicting the unobserved dichotomous variable, and is usually more powerful than (1). Approach (3) is most powerful, but for testing differences in means of 0.2,0.5 standard deviations, (2) is typically more than 95 percent as efficient as (3). Conclusions. The information loss from not observing actual values of dichotomous predictors can be quite large. Direct substitution is easy to implement and interpret and nearly as efficient as the PIMLE. [source]

Short-Term Reliability and Continuity of Emotional Availability in Mother,Child Dyads Across Contexts of Observation

INFANCY, Issue 1 2006
Marc H. Bornstein
Emotional availability (EA) is a prominent index of socioemotional adaptation in the parent,child dyad. Is EA affected by context? In this methodological study, 34 mothers and their 2-year-olds were observed in 2 different settings (home vs. laboratory) 1 week apart. Significant cross-context reliability and continuity in EA as measured with the Emotional Availability Scales emerged. Because EA is not affected by context, cross-context generalizations about EA status in the dyad may be warranted. This work further documents the adequate psychometric properties of emotional availability. [source]

Effectiveness of the auscultatory and pH methods in predicting feeding tube placement

JOURNAL OF CLINICAL NURSING, Issue 11-12 2010
e San Turgay
Aims and objectives., This study was designed to determine the effectiveness of the auscultatory and pH methods in predicting feeding tube location in critically ill patients. Background., There is confusion about how nurses should asses feeding tubes location at the bedside. The most common method for determining tube location is the auscultatory method. It is known that auscultation is an unreliable method and additional data relating to bedside methods are needed to assist nurses in making a decision regarding tube location. Design., A methodological study. Methods., The sample consisted of 44 new insertions of feeding tubes. Data from a total of 44 auscultations relating to tube position and gastrointestinal aspirates for pH were obtained from 32 critically ill adult patients ranging in age from 38,87 years. Results from the auscultatory and pH tests were compared with the location of the tube as determined by radiography. A total of 44 feeding tube applications were investigated using the auscultatory and pH methods and concurrently with X-rays to determine the feeding tube position. Nurses used the auscultatory method to predict tube position, a concurrent researcher aspirated fluid from the feeding tube, and samples were tested for pH within five minutes of radiographs taken to determine tube location. pH was measured with a test strip. Results., Mean pH level in the gastrointestinal aspirates was 4·23 (SD 1·20). Approximately 89% of the pH strip readings from gastrointestinal fluid were between 0,5. A pH of <5 successfully identified 90·4% of the 44 feeding tube cases. Conclusion., The pH method is effective in determining the feeding tube position, but the auscultatory method is not effective in determining the feeding tube position. Relevance to clinical practice., Simple bedside assessment of gastrointestinal aspirate pH is useful for predicting feeding tube position. [source]

Three-dimensional force measurements on oral implants: a methodological study

JOURNAL OF ORAL REHABILITATION, Issue 9 2000
J. Duyck
This paper describes a methodology that allows in vitro and in vivo quantification and qualification of forces on oral implants. Strain gauges are adapted to the outer surface of 5·5 and 7 mm standard abutments (Brånemark System®, Nobel Biocare, Sweden). The readings of the strain gauges are transformed into a numerical representation of the normal force and the bending moment around the X- and Y- axis. The hardware and the software of the 3D measuring device based on the strain gauge technology is explained and its accuracy and reliability tested. The accuracy level for axial forces and bending moments is 9.72 N and 2.5 N·cm, respectively, based on the current techniques for strain gauged abutments. As an example, an in vivo force analysis was performed in a patient with a full fixed prosthesis in the mandible. Since axial loads of 450 N and bending moments of 70 N·cm were recorded, it was concluded that the accuracy of the device falls well within the scope of our needs. Nevertheless, more in vivo research is needed before well defined conclusions can be drawn and strategies developed to improve the biomechanics of oral implants. [source]

Measurement of antepartum depressive symptoms during high-risk pregnancy

RESEARCH IN NURSING & HEALTH, Issue 1 2005
Judith A. Maloni
Abstract This methodological study was designed to replicate three previous studies of depressive symptoms, compare assessment of antepartum depressive symptoms among high-risk pregnant women using three standardized instruments, and evaluate the psychometric properties of the instruments. The sample consisted of 89 high-risk pregnant women treated with bed rest, of whom 37 remained hospitalized at 4 weeks. Depressive symptoms were measured by the Multiple Affect Adjective Checklist Revised (MAACL-R) Dysphoria construct, the Profile of Mood States (POMS) Depression scale, and the Center for Epidemiologic Studies Depression Scale (CES-D) across antepartum hospitalization. Internal consistency, test-retest reliability, and convergent validity were high. Depressive symptoms were high on admission as measured by all three instruments and significantly decreased across time when measured by the MAACL-R and POMS. © 2004 Wiley Periodicals, Inc. Res Nurs Health 28:16,26, 2005 [source]

ORIGINAL RESEARCH,OUTCOMES ASSESSMENT: Validation of the Female Sexual Distress Scale-Revised for Assessing Distress in Women with Hypoactive Sexual Desire Disorder

THE JOURNAL OF SEXUAL MEDICINE, Issue 2 2008
Leonard DeRogatis PhD
ABSTRACT Introduction., The concept of sexually related personal distress is currently central to the diagnosis of all female sexual dysfunctions (FSD). In the current study, we have focused on validating a slightly revised version of the Female Sexual Distress Scale (FSDS), the FSDS-Revised (FSDS-R), to enhance the sensitivity of the instrument with patients suffering from hypoactive sexual desire disorder (HSDD). In addition, we have attempted to extend the validation generalizability of the scale by demonstrating that both instruments possess reliability and discriminative validity in premenopausal women with HSDD. Aim., To assess the validity of the revised version of the FSDS, the FSDS-R, for measuring sexual distress in women with HSDD. Methods., A prospective methodological study carried out at 27 centers in North America enrolled 296 women aged 18,50 years with HSDD, another female sexual dysfunction (FSD), or no FSD. The subjects completed the FSDS-R at baseline, day 7, and day 28, with a 30-day recall at baseline and with a 7-day recall on days 7 and 28. Main Outcome Measures., Receiver operating characteristic (ROC) analyses of FSDS, FSDS-R, and FSDS-R item 13 were used for the differentiation of HSDD from no FSD, while intraclass correlation coefficient (ICC) was used to estimate test,retest reliability. Cronbach's coefficient alpha was used to measure the internal consistency of the FSDS-R and Pearson's correlation coefficient to assess FSDS, FSDS-R, and FSDS-R item 13 with different recall periods (7 and 30 days). Results., Mean total FSDS, FSDS-R, and FSDS-R item 13 scores with either recall period were significantly higher (P < 0.0001) in women with FSD or HSDD than in women with no FSD, showing both tests had discriminant validity. ROC analysis confirmed these findings, while an ICC of >0.74 showed the test,retest reliability of both scales, including FSDS-R item 13 alone, and Cronbach's coefficient alpha of >0.86 confirmed the internal consistency of both tests. Conclusions., Consistent with the FSDS, the FSDS-R demonstrated good discriminant validity, high test,retest reliability, and a high degree of internal consistency in measuring sexually related personal distress in women with HSDD. FSDS-R item 13 alone also demonstrated good discriminant validity and test,retest reliability. DeRogatis L, Clayton A, Lewis-D'Agostino D, Wunderlich G, and Fu Y. Validation of the female sexual distress scale revised for assessing distress in women with hypoactive sexual desire disorder. J Sex Med 2008;5:357,364. [source]

Cryopreservation technique: comparison of Test yolk buffer versus SpermCryo and vapour versus computerised freezing

ANDROLOGIA, Issue 1 2008
L. Paras
Summary Semen cryopreservation offers the possibility to maintain fertility over a long time period e.g. for male cancer patients. Although its use expands worldwide, there is no established method that can be referred to as an entrenched standard for routine laboratory use. Cryodamage is still a general phenomenon and the success of cryopreservation is affected on one side by the cryoprotective agent and on the other side by the technique of freezing. In this methodological study, we compared the newly offered SpermCryo (SC) with the standard used cryoprotectant Test yolk buffer (TYB). We could show that TYB is superior to SC. In addition, we compared the two mainly used techniques for cryopreservation: computerised slow-stage freezing versus nitrogen vapour fast freezing. Regarding the sperm post-thaw motility and viability, no significant difference was found between these two methods. In conclusion, TYB can be recommended as a cryomedium of first choice and the appropriate freezing technique can be selected according to the local facilities of the institution. [source]

Circadian Variation in QT Dispersion Determined from a 12-Lead Holter Recording: A Methodological Study of an Age- and Sex-Stratified Group of Healthy Subjects

Validity and responsiveness of the Osnabrück Hand Eczema Severity Index (OHSI): a methodological study

BRITISH JOURNAL OF DERMATOLOGY, Issue 1 2009
M. Dulon
Summary Background, The Osnabrück Hand Eczema Severity Index (OHSI) is a scoring system for the assessment of the severity of hand eczema (HE). Objective, To assess the clinimetric value of the OHSI and to validate the longitudinal responsiveness of the OHSI using the Manuscore as a gold standard. Methods, OHSI and Manuscore scores were compared before and after 3 weeks' inpatient treatment of 62 patients with occupational HE. Correlation coefficients and 95% limits of agreement were calculated and the ability of OHSI to identify severe HE was analysed. The responsiveness of the OHSI in monitoring skin changes over time was evaluated by calculating effect sizes. Results, High correlation was found between the OHSI and Manuscore at both scoring occasions (around rs = 0·77). Differences between both measurements were within the 95% limits of agreement for 94% of patients, with a tendency for the OHSI to underestimate the severity at very low and at very high values compared with the Manuscore. Responsiveness to change was good. Both instruments showed significant improvement between the scoring occasions. Using the OHSI values, the proportion of classification to the correct tertile of score change was 69%. Effect size from untreated to treated was 0·6 for the Manuscore and 1·1 for the OHSI, with higher effect sizes in individuals with severe HE. Conclusions, Even though the OHSI allows less differentiation than the Manuscore, it shows adequate validity and responsiveness to change. Thus the OHSI is suitable for both monitoring the severity of HE and the effects of treatment. [source]

Comments on ,Validity and responsiveness of the Osnabrück Hand Eczema Severity Index (OHSI): a methodological study'

BRITISH JOURNAL OF DERMATOLOGY, Issue 2 2009
C.J. Apfelbacher
No abstract is available for this article. [source]

Comments on ,Validity and responsiveness of the Osnabrück Hand Eczema Severity Index (OHSI): a methodological study': reply from authors

BRITISH JOURNAL OF DERMATOLOGY, Issue 2 2009
M. Dulon
No abstract is available for this article. [source]