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PubMed1996

Transpedicular reduction and stabilization for postlaminectomy lumbar instability.

This study retrospectively reviewed the outcomes of 17 patients with postlaminectomy lumbar instability treated by transpedicular reduction and stabilization. The criteria of instability were defined strictly by both the clinical symptom of "instability catch" and the radiological findings that fulfilled Nachemson's criteria. Low back pain and/or sciatica that interfered largely with the patients' work or quality of life were the indications for this treatment. All the operations were performed by one surgeon with the same spinal instrumentation system-"AO internal fixator". The follow-up period was between 16 and 36 months (mean 24 months). Face to face questionnaire revealed that this treatment modality is encouraging. Fourteen patients (82%) had complete or nearly complete relief from all the pre-operative symptoms. Two (12%) had partial relief of the symptoms that required a subsequent discectomy or wider laminectomy. Only one case (6%) with osteoporosis remained unchanged after the operation. On the follow-up radiographs, sixteen patients (94%) showed good alignment and solid arthrodesis of the treated motion segment. These radiological findings correlated quite well with the absence of the clinical symptom of "instability catch". A common, but acceptable, complication found in this series was a variable degree of low back stiffness secondary to the instrumentation. Fracture of the screw was found in one patient and pull out of the screw was found in another patient. However, they did not elicit detectable symptoms. Osteoporosis, concomitant disc herniation and persistent spinal stenosis at/or adjacent to the operated level were the three main factors that may contribute to unsatisfactory results secondary to this treatment. These problems remain to be resolved in the future.

Adult↗

PubMed1988

[Quality assurance in Riva-Rocci blood pressure measurement: simultaneous sphygmomanometry with open and covered pressure display].

The indirect measurement of arterial blood pressure according to Riva-Rocci is one of the most frequently performed medical diagnostic procedures. When properly performed, this method yields accurate readings compared with intraarterial measurements. However, measurements by means of conventional sphygmomanometers are subject to observer error and variability. Therefore, to eliminate important sources of bias (terminal digit preference of the observer, rate of inflation and deflation of the cuff), and to quantify interobserver variability, a new sphygmomanometer has been developed. The new instrument makes possible "simultaneous-blind" blood pressure readings by two observers, according to the Riva-Rocci method. Simultaneous-blind blood pressure readings were made by four observers with experience in blood pressure determination. In 448 measurements made under resting conditions, values obtained by different observers with the new device were very consistent with each other: there were no differences in 50% of systolic and 43% of diastolic measurements. Differences of more than 5 mmHg were observed only in 9% of the systolic and 11% of the diastolic measurements. In 165 measurements made during exercise, the differences between blood pressure readings by different observers were larger (more than 5 mmHg in 40% of systolic and 35% of diastolic values). This variability among observers may be substantial in blood pressure readings made in therapeutic and epidemiologic studies, even when the observers are carefully selected and trained. Compared with the conventional open measurements, blind measurements (n = 100) gave mean values 2 mmHg lower, depending on heart rate and cuff deflation rate. The new sphygmomanometer allows quantification and control of the variability among observers during both open and blind measurements.

Adult↗

PubMed1989

Test of a noninvasive instrument for measuring hemoglobin concentration.

A colorimetric instrument for the noninvasive quantification of hemoglobin, designed using color shades resembling those observed in the conjunctiva, was tested. The instrument's colors are contrasted against the color of the conjunctiva to measure hemoglobin content. Sensitivity, specificity, negative predictive value, and false-negative value were estimated to test the instrument's accuracy; kappa coefficients were used to estimate inter- and intraobserver variability. Physician field evaluations of conjunctiva color for the screening of anemia, reported in the literature, have had sensitivities and specificities as high as 70%. Readings with the instrument demonstrated a 63% sensitivity, 72% specificity, and 38% false negatives for screening hemoglobin values of less than or equal to 13 g/dl. The interobserver kappa coefficients for three pairs of readers were good to excellent for the same hemoglobin screening value. Statistically significant differences were noted, however, between observers during the reliability test. The instrument can be used by unskilled personnel to improve their decision-making about whom to send for further care or for supplementation with iron.

Anemia↗

PubMed2004

Health and well-being in early adolescents using Rogers' science of unitary human beings.

The purpose of this study was to examine the relationship of perceived field motion and human field rhythms to perceived health status, health conception, and well-being in early adolescents to determine which health-related variables are most compatible with Rogers' science of unitary human beings. The sample of 142 early adolescents responded to the study instruments in classrooms. The correlations between perceived field motion and each of the other variables were statistically significant, and increased in magnitude from perceived health status to health conception to well-being. These results give credence to Rogers' evolving philosophical belief that the term well-being is more compatible than health in her science.

Adolescent↗

PubMed2002

[Health-related quality of life in patients with chronic pain].

AIMS: An empirical comparison of the performance characteristics of 3 generic health-related quality of life (HRQL) measures in pain patients. METHODS: The Nottingham Health Profile (NHP), the Medical Outcomes Study 36-item Short-Form Health Survey (SF-36), and the German Life Satisfaction Scale (FLZ-M) by Henrich et al. were simultaneously employed in a multicenter survey measuring the impact of pain on quality of life. The HRQL- instruments were incorporated into the German Pain Questionnaire (pain variables, CES-D, Pain Disability Index). RESULTS: Characteristics of 3294 pain patients of 13 pain facilities are detailed in tables 1-3. Six of the 8 SF-36- and 4 of the 6 NHP-scales show satisfactory item-total correlations, bottom- and ceiling-effects, and internal consistency. FLZ-M reliabilities are satisfactory. The item weighting procedure of the FLZ-M proves to be unnecessary. Principle component analyses result in 7 factors for the SF-36 and the NHP. Six of the SF-36-factors are fairly homogeneous. The heterogeneity of the NHP- factors is marked. Correlations of the HRQL scales with depression (CES-D), anxiety (STAI) and physical functioning (FFbH-R-18) are high in all related contents. All instruments discriminate well between headache and back pain patients, between several pain grades (v. Korff) and the 3 Mainz pain chronicity stages. CONCLUSIONS: The SF-36 has satisfactory to good psychometric properties in pain patients, the NHP item selection has to be improved. The FLZ-M weighting can be eliminated. The shortcomings of the SF-36 can be overcome by adding short scales on role functioning and pain (modular approach).

Adult↗

PubMed2004

Fetal magnetocardiography: time intervals and heart rate variability.

Biomagnetism in the perinatal domain has been dominated by fetal cardiology, and early work pointed out the potential of both fetal cardiac time intervals (CTI) and heart rate variability (HRV) for future clinical applications. Recent improvements in instrumentation have permitted numerous groups to investigate a substantial number of healthy fetuses in these two areas and to lay the groundwork for a delineation of normal ranges. With respect to fetal CTI it is now clear that in particular the duration of P wave, PR interval and QRS complex reflect fetal growth and development. Preliminary studies have shown that the age-adjusted CTI are shorter in growth-retarded fetuses and altered in cases of structural cardiac defects and in specific types of arrhythmia. Less work has been published on MCG-determined fetal HRV although parameters from both the time and frequency domains as well as complexity have been examined. Concomitant with the gradual change in heart rate during pregnancy, increases in time domain variables and complexity have been described for normal pregnancies. Furthermore, gestational age-related changes in specific spectral bands have been noted and increases in power have been documented at frequencies which are associated with fetal breathing movements. The fact that little has been reported to date on discriminatory power with respect to pathological states may be due to the lack of extended data acquisition in a clinical setting documenting acute states. Nonetheless, it may be expected that both fetal HRV and CTI will supplement standard fetal surveillance techniques in the near future.

Cardiotocography↗

PubMed1987

Validity and reliability of the Experience-Sampling Method.

To understand the dynamics of mental health, it is essential to develop measures for the frequency and the patterning of mental processes in every-day-life situations. The Experience-Sampling Method (ESM) is an attempt to provide a valid instrument to describe variations in self-reports of mental processes. It can be used to obtain empirical data on the following types of variables: a) frequency and patterning of daily activity, social interaction, and changes in location; b) frequency, intensity, and patterning of psychological states, i.e., emotional, cognitive, and conative dimensions of experience; c) frequency and patterning of thoughts, including quality and intensity of thought disturbance. The article reviews practical and methodological issues of the ESM and presents evidence for its short- and long-term reliability when used as an instrument for assessing the variables outlined above. It also presents evidence for validity by showing correlation between ESM measures on the one hand and physiological measures, one-time psychological tests, and behavioral indices on the other. A number of studies with normal and clinical populations that have used the ESM are reviewed to demonstrate the range of issues to which the technique can be usefully applied.

Activities of Daily Living↗

PubMed1993

Declining bone loss rate variability with increasing follow-up time.

Bone loss rates are believed to vary substantially among post-menopausal women. The belief, however, might be largely based upon comparisons of loss rates measured with considerable error. This issue arises because the precision of the bone mass instrumentation (1-2% errors in measuring bone mass) is similar in magnitude to the loss rate (typically 1-2% of bone mass per year). The 'true' variability in loss rates, however, can be estimated by adjusting for instrument errors. An equation is presented which estimates the true variability in loss rates from a study sample. The adjustment was examined using a cohort of post-menopausal, Japanese-American women living in Hawaii. The study examined the calcaneus, distal, and proximal radius sites. The results suggest that measurement errors did not markedly inflate the bone loss variability. Even after adjustment for measurement errors considerable variability in loss rates remained. The variability was examined for various follow-up durations. Both the observed and adjusted loss rates had smaller standard deviations over long intervals than over short intervals. This result suggests that the more extreme rates of change in bone mass over a year or two were often not sustained. The implications of this finding for sample size calculations in longitudinal studies are examined. The results also indicate that the length of follow-up and instrument precision should be taken into consideration when comparing the proportion of fast losers between populations.

Absorptiometry, Photon↗

PubMed2002

Spatial patterns of tuberculosis incidence in Cologne (Germany).

In many European countries, the decline of tuberculosis notification rates levelled off in the mid 1980s. Germany has been facing only a very modest resurgence of tuberculosis (TB) in the early 1990s, but until now, the notification rate does not yet fulfil the WHO definition of a low incidence country. Mainly immigration from high incidence countries is held responsible for the delayed decline and temporary increase of TB. This paper seeks to investigate the inner-urban strength of association between tuberculosis and several potential risk factors in the city of Cologne using geographical and statistical methods within a small-area division based, GIS-supported ecological study, which never before has been conducted for a German city. Standardised annual TB incidence rates for 78 urban subdistricts between 1986 and 1997, disaggregated by age, have been analysed. Twelve independent variables representing contemporary ethnic and socioeconomic conditions are used to calculate Poisson regression models. For the entire population and for the <60 age group, a strong positive association was found between tuberculosis incidence and share of immigrants. Interestingly enough the share of German-origin immigrants from eastern Europe was seen not to be instrumental in increasing TB rates. Reflecting strong ecological correlations between variables depicting economic conditions and TB as well as immigration variables, the deprivation of certain ethnicities rather than high prevalence immigration background is inferred to be significant to TB level. As for the 60 + age group regression analysis fails to model the TB incidence patterns sufficiently it seems reasonable to assume an autonomous, spatially disaggregated TB epidemic of the elderly, echoing a severe post-war epidemic by reactivation, only marginally associated with contemporary living conditions, but contributing substantially to the current TB incidence level. This assumption is reinforced by further results of the statistical analysis (deviance of regression null models, testing for Normal distribution, time trends). It could be shown that in Cologne the HIV/AIDS epidemic is not significantly influencing the TB incidence rate of men aged 30-49 being the most AIDS-afflicted population subgroup.

Adult↗

PubMed2000

Environmental press and adaptation to disability in hospitalized live-alone older adults.

PURPOSE: This study examined the ability of personal competency variables at the time of hospital discharge to predict primary instrumental activities of daily living (IADLs) and secondary outcomes (living arrangements) in a sample of 194 urban, live-alone, older adults who had a new onset disability. DESIGN AND METHODS: Consecutively admitted medical rehabilitation patients, 72% women and 85% African American, participated in the study. Using path analysis, three of the four competency variables collected at the time of hospitalization (cognition, medical burden, activities of daily living) predicted IADLs at 3 and 6 months after hospitalization (e.g., cooking, telephone use, money management). IADLs, in turn, predicted living arrangements at 3 and at 6 months after hospitalization. RESULTS: The findings provided strong support for the importance of assessing a broad range of competency variables when investigating adaptation to disability. IMPLICATIONS: The increased understanding of adaptation in live-alone older adults with a new-onset disability is particularly timely given the increase in live-alone older adults and the dire consequences associated with change in living arrangement (i.e., mortality and morbidity) in this group.

Activities of Daily Living↗

PubMed1997

Determinants of functional status in healthy Italian nonagenarians and centenarians: a comprehensive functional assessment by the instruments of geriatric practice.

OBJECTIVE: To evaluate the physical ability and psychocognitive status of a population more than 90 years of age with regard to sociodemographic, behavioral, and biomedical variables known to affect functional status in old age. DESIGN: A survey design was used. SETTING: Emilia Romagna, Northern Italy. PARTICIPANTS: Eighty-four healthy community-dwelling subjects aged 90 to 106 years. MEASUREMENTS: Sociodemographic variables, health behavior, anthropometric indices, and serum DHEAS levels were recorded. Functional assessment was performed by instruments currently used in geriatric practice: the Mini-Mental State Examination (MMSE), Geriatric Depression Scale (GDS), and Activities of Daily Living (ADL) scale. A stepwise multiple regression analysis was performed. RESULTS: GDS scores correlated directly with MMSE scores and inversely with ADL severity scores. Poor education, institutionalization, sensory impairment, muscular mass loss, and lower DHEAS levels were the variables with the highest correlation to functional impairment. Smoking, alcohol consumption, and marital status were relatively unimportant. An inverse association was found between DHEAS levels and dependency scores of single ADLs (continence, mobility). CONCLUSION: Impaired cognitive and physical ability with no increase in depression prevalence was found in a sample of subjects more than 90 years of age free of major age-related disease. Muscular mass and DHEAS levels seem to play a role in maintaining physical independence. In turn, physical independence, as well as social and cultural factors, strongly affect the compliance of long-lived subjects with psychocognitive tests currently used in the clinical evaluation of younger old people, suggesting that these instruments are not reliable for screening for cognitive impairment and depression in the oldest old subjects.

Activities of Daily Living↗

PubMed2000

A portable instrument for non-invasive monitoring of beat-by-beat cardiovascular haemodynamic parameters based on the volume-compensation and electrical-admittance method.

A new, portable instrument has been developed for simultaneous monitoring of blood pressure, cardiac output and other cardiovascular haemodynamic variables. The measurements are based on the volume-compensation method and the transthoracic electrical admittance method. The instrument is small and light and can be carried by the subject. The portable unit controls the measurement procedures, performs the blood pressure and cardiac output measurement, processes signals and stores almost 32,000 beats of time-series data in a fully automated manner. A conventional personal computer is used to initialize the measurement system, and to reproduce and evaluate the measurement data. The measurement system provides a means to evaluate in detail, without restriction, the subject's cardiovascular haemodynamic responses to daily physical activities as well as to various psycho-physiological stresses. The paper describes a new, portable, cardiovascular haemodynamic instrument and in-the-field test results. Twelve subjects are monitored for trials, 60-210 min, and fewer than 3% of the data in each trial are artifactual. Artefacts are due mainly to body movements.

Adult↗

PubMed2002

Surface analysis of ProFile instruments by scanning electron microscopy and X-ray energy-dispersive spectroscopy: a preliminary study.

AIM: The purpose of this preliminary study was to analyze surface irregularities on ProFile nickel-titanium (NiTi) rotary instruments before use, after sterilization by two different methods and after instrumentation of molar root canals. METHODOLOGY: Five new ProFile NiTi rotary instruments with 0.04 taper, size 20, five instruments with 0.04 taper, size 25 and five with 0.06 taper, size 20 were analyzed by scanning electron microscopy (SEM) and X-ray energy-dispersive spectroscopy (EDS). The instruments were then divided into two groups: three of each taper and size were sterilized in a dry heat sterilizer, whilst two of each taper and size were sterilized in an autoclave. After inspection by the same techniques, the files were used to instrument six molar root canals, and again analyzed by SEM/EDS. RESULTS: Together with the usual machining defects, a variable amount of material containing mainly carbon and sulphur was found on the surface of new instruments. This material was not removed by standard cleaning and sterilization procedures. The use of the files for instrumentation of root canals eliminated a considerable amount of the adhered substance, but deposits rich in calcium and phosphorus accumulated on the remaining impurities. CONCLUSIONS: The adherence of dentine on surface deposits found on new ProFile instruments requires special cleaning, prior to sterilization.

Calcium↗

PubMed1978

Blood pressure of children, ages 2 1/2-5 1/2 years, in a total community--the Bogalusa heart study.

Eighty per cent of all identified children 2 1/2-5 1/2 years old in a total geographic community in Bogalusa, Louisiana, were examined for cardiovascular disease risk factor variables, including blood pressure (BP), anthropometric measurements, and blood lipids. Blood pressure was measured by three instrument types, each with three readings, according to a rigid, randomized design. Results from the three instruments were compared, and potential biases for each instrument are listed. All observations on the children were analyzed by multiple regression with BP as the dependent variable. After controlling for the mood of the child, the authors found that some index of body size was positively related to BP, whereas age, race, and serum lipids were not consistently related. The regressions of blood pressure on height as well as on log weight fit straight lines. These results conform with the findings for the 5- to 14-year-olds in this community. The basal or fundamental reference blood pressure is likely to rise gradually from birth to the age of incipient adult stature, and to be linearly related to height and to log weight. Changes observed over time are needed to relate BP levels in childhood to the early natural history of essential hypertension.

Age Factors↗

PubMed1996

Development of the Quebec User Evaluation of Satisfaction with assistive Technology (QUEST).

This study's purpose was to develop a clinical instrument designed to evaluate user satisfaction with assistive technology devices. This paper describes the methodology used to develop the instrument entitled the Quebec User Evaluation of Satisfaction with assistive Technology (QUEST). Based on the theoretical and practical foundations of assistive technology as well as on the concept of satisfaction, preliminary versions of the instrument were created and examined by a panel of team participants. After the panel's recommendations were incorporated, a pretest of the revised instrument was conducted and the final French version of QUEST emerged. The originality of QUEST lies in its inter-activeness and user-directed approach to assessing satisfaction with assistive technology. From a set of 27 variables, the user is asked to indicate the degree of importance he/she attributes to each of the satisfaction variables and then to rate his/her degree of satisfaction with each of the variables considered (quite or very) important. While QUEST remains a clinical instrument undergoing pilot testing, it holds much promise in our quest for a reliable and valid means of assessing assistive technology outcome from the user's perspective.

Humans↗

PubMed1994

Relationship among accommodation, focus, and resolution with optical instruments.

We studied instrument myopia as an overall effect consisting of interactions among the observer's accommodation and resolution during instrument viewing and the manner in which the instrument is focused. Previous investigations of instrument myopia generally have been limited to only one of these variables. Our results are consistent with the dark-focus-bias theory of accommodation, which holds that accommodation tends to seek its resting point, or dark focus, whether or not the observer is viewing through an optical instrument. The amount of accommodation measured during instrument viewing was found to be dependent on instrument design features that modulate the bias of accommodation for the dark focus.

Accommodation, Ocular↗

PubMed1996

Factors related to quality of life and functional status in 50 patients with head and neck cancer.

Quality of life (QOL) and functional status (FS) have become important outcome measures in cancer therapy. Valid and reliable instruments recently have been developed for examining QOL and FS in patients with head and neck (HN) cancer. The present study evaluated the relationships of QOL and FS to physical and psychological variables assumed to affect QOL and FS. Fifty patients were evaluated up to 6 years after HN cancer surgery using one general QOL instrument and three HN-specific instruments. Analysis of variance showed physical variables such as tumor site to be related to HN-specific scores, while psychosocial variables such as marital status were related to general QOL scores (P < or = .05). Several relationships were seen between physical or psychosocial variables and FS or QOL measures; however the relationships were not as strong or direct as expected.

Adult↗

PubMed2005

Comparability of retinal nerve fiber layer thickness measurements of optical coherence tomography instruments.

PURPOSE: To compare retinal nerve fiber layer (RNFL) measurements between two ocular coherence tomography (OCT) instruments (OCT 2000 and Stratus OCT; Carl Zeiss Meditec, Dublin, CA) and compare their diagnostic precision. METHODS: One hundred thirty-nine consecutive subjects were imaged (3 x 3.4-mm diameter circular scans) on the same day with each instrument. Thirty-five patients were excluded due to poor-quality images. RNFL thicknesses measured by the two instruments were compared, and receiver operating characteristic (ROC) curves were used to determine diagnostic precision. RESULTS: A randomly selected eye of each of 104 participants (28 with open-angle glaucoma, 40 with suspected glaucoma, and 36 healthy subjects) was analyzed. RNFL thickness measurements generally were thicker with OCT 2000 than with Stratus OCT. The difference in global RNFL thickness between instruments was within 20 microm in 66 (65%) of subjects and within 10 microm (the instrument's limit of resolution) in 25 (25%) subjects. Application of a correction factor to OCT 2000 measurements predicted Stratus OCT RNFL thickness within 10 microm of the observed measurement in 75% of the eyes. For both instruments, highest ROC curve areas (better discrimination between glaucomatous and normal eyes) were found in the inferior sector. Discrimination using global RNFL thickness was better with Stratus OCT than OCT 2000 (P = 0.043). CONCLUSIONS: RNFL thickness measurements measured by OCT 2000 can be approximated to measurements made by Stratus OCT using correction factors calculated by this study. However, there remains considerable variability that exceeds the limits of resolution afforded by the instruments themselves. Therefore comparisons between instruments using these approximations should be interpreted with caution.

Aged↗