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PubMed1994

Thermodontic stimulator--a new technology for assessment of thermal dentinal hypersensitivity.

A clinical investigation of the reproducibility of threshold and pain temperature scores obtained from use of the Thermodontic Stimulator (TDS) is reported. The TDS is designed for accurate clinical testing of thermal dentinal hypersensitivity. This instrument employs a variable stimulus/fixed response approach to clinical testing of thermal dentinal hypersensitivity. The TDS consists of a probe in a handpiece, a patient signaling device (joystick), a computer, and interface electronics. The TDS provides a precise means of assessing and recording the temperature which elicits a response to thermal stimulation from the subject being evaluated. Two temperatures are recorded. The threshold temperature is recorded when the patient is first able to sense that a cold stimulus has been applied to the tooth. The second score, pain temperature, is recorded when the subject first notices discomfort. Twenty-two subjects participated in this study. Results obtained from the 21 subjects who completed this study (one subject dropped out for non-compliance) demonstrated a reproducibility standard deviation of 1.1 degrees C for the threshold temperature, and 2.8 degrees C for the pain temperature for the duration of the study. There was a good degree of correlation between the measurements of any two test days (Pearson's correlation coefficient). There was no significant difference between the mean pain temperature scores of any two testing days.

Cold Temperature↗
PubMed1998

[Patient satisfaction after inpatient rehabilitation: different results at different follow-up times?].

UNLABELLED: Different Results at Different Times of Questioning? In 1994 a quality assurance programme for the German medical rehabilitation system was introduced by the national association of pension funds. One of its five parts focussed on patients' satisfaction and health effects. Both domains were to be assessed by postal questionnaires. The first section of the instrument enquired about patients' perceptions and evaluations of both rehabilitation structures and processes. It is well known that satisfaction surveys tend to underestimate the true level of criticism due to social desirability bias. This is especially problematic in the context of quality assurance programmes where criticism can be seen as one driving force of improvement. The magnitude of the bias depends on many factors. In this study we tested the influence of different time intervals between discharge from rehabilitation clinic and first postal contact. DESIGN: We conducted an experimentally varied satisfaction survey among four groups of rehabilitands. If necessary, the first postal questionnaire was followed by two reminders. SETTING: One Bavarian pension fund for blue collar workers. PATIENTS: 520 rehabilitands were recruited from various rehabilitation clinics specialized in muskuloskeletal disorders. About 70% suffered from nonspecific back pain. They were randomly allocated to one of the following time intervals between discharge and postal questionnaire: one, four, eight and twelve weeks. INSTRUMENTS AND TARGET VARIABLES: All patients received an identical questionnaire with 67 items and several subscales. We compared the extent of dissatisfaction between the four groups. RESULTS: The response rate (after two reminders) showed a linear decrease from 97% (postal questionnaire after one week) to 83% (12 weeks). The extent of dissatisfaction did not change systematically though there was a (statistically nonsignificant) tendency towards higher levels of criticism at week twelve. CONCLUSIONS: An experimental variation of time intervals between discharge from rehabilitation and first postal contact does not seem to influence the extent of reported dissatisfaction though it clearly influences the response rate: The later the sending out the lower the response rate. Taking into account additional administrative and organisational aspects of the programme we propose to send out satisfaction questionnaires between 8 and 10 weeks after rehabilitation.

Adult↗
PubMed2005

Small artery compliance in cirrhotic patients during total paracentes.

BACKGROUND: Hemodynamic changes, including systemic vascular resistance, in cirrhotic patients during massive paracentesis have been reported, but large and small artery compliance has not yet been investigated. OBJECTIVE: To investigate hemodynamic variables, including small and large artery compliance, in cirrhotic patients during total paracentesis. METHODS: The study included 15 cirrhotic patients admitted for an episode of tense diuretic-resistant ascites. Hemodynamic variables including vascular compliance were measured using an HDI pulse wave cardiovascular profiling instrument CR-2000. The variables were measured in these patients before, immediately after, and 24 hours following large volume (mean 5.6 L) paracentesis. RESULTS: Cardiac output increased immediately after paracentesis due to increment in stroke volume, with no change in heart rate. However, 24 hours later the cardiac output decreased to below the basal level. The fluctuation was statistically significant (P < 0.05). There was no change in large artery compliance, but small artery compliance increased after paracentesis (P < 0.05) and partially retumed to the basal level after 24 hours. Systemic vascular resistance measurement showed the same pattern of change: vasodilatation occurred during paracentesis and was attenuated 24 hours later. CONCLUSIONS: Large volume paracentesis with albumin replacement caused an accentuation of the vasodilatation (small but not large artery) already present in these patients. This may be the first sign of enhanced vasodilatation due to large volume paracentesis before the clinical expression of impaired hemodynamics and deterioration of renal function.

Adult↗
PubMed1998

Analysis of carbonaceous aerosols: interlaboratory comparison.

Carbonaceous aerosols are present in many workplace and environmental settings. Some of these aerosols are known or suspect human carcinogens and have been linked to other adverse health effects. Exposure to diesel exhaust is of particular concern because it has been classified as a probable human carcinogen and use of diesel-powered equipment is widespread in industry. Because previously used methods for monitoring exposures to particulate diesel exhaust lack adequate sensitivity and selectivity, a new method was needed. A carbon analysis technique called the thermal-optical method was evaluated for this purpose. In thermal-optical analysis, carbon in a filter sample is speciated as organic and elemental (OC and EC, respectively). When the thermal-optical method was initially evaluated, only one instrument was available, so interlaboratory variability could not be examined. More recently, additional instruments were constructed and an interlaboratory comparison was completed. Eleven laboratories participated in the study, including four in Europe that employ an alternative thermal technique based on coulometric detection of CO2. Good agreement (RSDs less than or equal to 15%) between the total carbon results reported by all laboratories was obtained. Reasonable within-method agreement was seen for EC results, but the EC content found by the two methods was differed significantly. Disagreement between th OC-EC results found by the two methods was expected because organic and elemental carbon are operationally defined. With all filter samples, results obtained with the coulometric method were positively biased relative to thermal-optical results. In addition, the alternative method gave a positive bias in the analysis of two OC standard solutions. About 52% and 70% of the carbon found in two aqueous solutions containing OC only (sucrose and EDTA, respectively) was quantified as elemental,while EC contents of about 1% and 0.1% (respectively) were found by the thermal-optical method. The positive bias in the analysis of the OC standards is attributed largely to inadequate removal of OC during the first part of the analysis; lack of correlation for pyrolytically formed carbon (char) also is a factor. Results obtained with a different thermal program having a higher maximum temperature were in better agreement with the thermal-optical method.

Aerosols↗
PubMed2001

Age-related changes in spatial and temporal gait variables.

OBJECTIVE: To extend recent findings describing the effect of age on spatial and temporal gait variables. DESIGN: Experimental. SETTING: A gait analysis laboratory. PARTICIPANTS: Two experiments with healthy nonfallers were conducted. Experiment 1 included 33 subjects (n = 15, 72.13 +/- 3.96yr; n = 18, 25.06 +/- 4.02yr); and experiment 2 included 24 subjects (n = 14, 75.57 +/- 6.15yr; n = 10; 28.10 +/- 3.48yr). INTERVENTIONS: The effect of age, walking velocity, shoe condition, and performance of an attention-splitting task on gait variables was investigated. MAIN OUTCOME MEASURES: Temporal and spatial gait variables were quantified using an instrumented surface across which subjects walked. The independent variables were walking velocity variability, stride length variability, stride width variability, and stride time variability. RESULTS: Stride width variability of older adults was significantly larger than that of younger adults in both experiments. The remaining gait variables demonstrated nonsystematic or no age-related differences. CONCLUSIONS: With the exception of stride width variability, the variability of the remaining gait variables of interest were insensitive to the speed at which subjects walked, whether the subjects were wearing shoes or not, and performing an attention-splitting task while walking. These findings contribute to an emerging interpretive framework established by similar work published by others regarding gait variability.

Adult↗
PubMed1989

Issues for quality assurance in clinical flow cytometry.

An increasing number of clinical laboratories are using flow cytometry to analyze cells stained with fluorescent antibodies or dyes. Many articles discuss the analytical performance of immunofluorescent assays and DNA staining procedures. However, quality assurance transcends the performance of analytical methods and includes preanalytic, analytic, and postanalytic phases of the test procedure. This review focuses on preanalytic and analytic factors that affect the results of flow cytometric analysis of cells stained with fluorescent antibody or dyes specific for nucleic acid. The article reviews the controls used to assess instrument performance followed by a discussion of biological variables, and reagent, methodological, and instrumental factors that may affect the interpretation of these results.

Antigens↗
PubMed2001

Responsiveness of generic and specific measures of health outcome in low back pain.

STUDY DESIGN: A longitudinal study using patient questionnaires was performed. OBJECTIVE: To compare the discriminatory power and responsiveness of the Aberdeen Back Pain Scale (ABPS), the Roland Disability Questionnaire (RDQ), and the EuroQol in patients with low back pain. SUMMARY OF BACKGROUND DATA: A number instruments specific to low back pain have not been compared for measurement properties. The EuroQol is a widely used generic instrument that has not been compared with specific instruments in patients with back pain. METHODS: A questionnaire incorporating the Aberdeen Back Pain Scale, the Roland Disability Questionnaire, and the EuroQol was completed by patients taking part in a clinical trial of exercise treatments for back pain. Patients completed follow-up questionnaires at 6 weeks, 6 months, and 1 year. The discriminatory power of these instruments was assessed against variables relating to activity limitations, medication, and comorbidity. Responsiveness was assessed using standardized response means. RESULTS: The questionnaire was completed by 187 patients taking part in the clinical trial. The Aberdeen instrument was found to be the most powerful at discriminating between different groups of patients on variables relating to activity limitations, medication, and comorbidity. The specific instruments demonstrated good levels of responsiveness, with the Aberdeen instrument producing the largest standardized response means. The Aberdeen instrument was more responsive to the smaller changes experienced by the control group, but was less powerful than the Roland at measuring differences in the levels of change between the two groups of patients at two of the three follow-up assessments in the trial. The EuroQol demonstrated a moderate level of responsiveness. CONCLUSIONS: The two specific instruments are capable of greater levels of discrimination between groups of patients, and are more responsive over time than the generic EuroQol. The Aberdeen instrument performed most satisfactorily in relation to these criteria, but the Roland instrument was more sensitive to differences between the two groups in the clinical trial. The measurement properties of these two instruments reflect their origin: The Aberdeen instrument is based on clinical questions, whereas the Roland instrument is based on the generic Sickness Impact Profile. Instrument content should be carefullyconsidered when selecting instruments for applications, including clinical trials.

Adolescent↗
PubMed2004

Dynamics of neural coding in the accumbens during extinction and reinstatement of rewarded behavior.

Neural correlates of reward-seeking behavior are observed in the nucleus accumbens (NAC). The dependence of these correlates upon the presence of a reward was studied by comparing the behavioral correlates observed when the presence of the reward was manipulated within a single behavioral session. Rats were well-trained on a continuous reinforcement instrumental task reinforced by 0.1 ml drops of 5% sucrose. Extracellular single-unit neural activity was recorded from electrode arrays implanted into the NAC when instrumental behavior was and then was not reinforced with sucrose (within-session extinction). A variable delay between the instrumental response and the sucrose delivery allowed for separation of neural activity related to these task events. A spike activity increase around the time of the instrumental response was the most common behavioral correlate, while a decrease in spike activity upon sucrose delivery was the second most common behavioral correlate. Following removal of the reinforcer, subjects continued to perform the instrumental response, allowing for the examination of response-related spike activity under extinction conditions in which the response was no longer reinforced by sucrose. A majority of the response-related neural activity patterns were lost when sucrose was no longer available. New neural responses also were detected during this period. For some subjects, the reinforcer was again made available during the same session. Encoding of the primary behavioral events during this period of reinstated reinforcer was similar, but not identical, to that observed during the first period of reinforced responding. These findings reveal that instrumental task-associated spike activity within the NAC is partially dependent upon the presence of the reinforcer, and that encoding across the population is distinct under reinforced and extinction conditions.

Animals↗
PubMed2002

Flexible ureteroscopes: a user's guide.

OBJECTIVE: To compare, quantitatively and qualitatively, four small-diameter flexible ureteroscopes. MATERIALS AND METHODS: Four flexible ureteroscopes from different manufacturers, i.e. the DUR-8 (ACMI, Southborough, MA, USA), Olympus UPF-3 (Keymed, Southend-on-Sea, UK), Storz 11274AA (Karl Storz GmbH, Tuttlingen, Germany) and the Wolf 9 F (Henke Sass Wolf GmbH, Tuttlingen, Germany), were assessed quantitatively by measuring the active tip deflection and irrigation flow rate with laser fibres (200 micro m, 365 micro m), an electrohydraulic lithotripter (1.9 F) and grasping forceps (3 F) in position. They were then assessed subjectively by two endourologists who scored them, using a visual analogue scale (maximum 10), for insertion, deflection mechanism, manoeuvrability, rigidity, image quality and overall satisfaction. RESULTS: All the endoscopes are < 9 F at the tip, although the length of the smallest diameter (bevelled tip vs section of shaft) was variable. Tip deflection was 87-100% of the manufacturers' specifications and decreased by similar percentages with instruments in the working channel. The irrigation flow rate was comparable for instruments with a 3.6 F working channel (72-88 mL/min with an empty working channel), although much greater for the Wolf, which has a 4 F channel (116 mL/min). Direction and image size were nearly identical, as was the field of view, apart from the Wolf (60 degrees vs 90 degrees ). There was agreement in the user assessment for three instruments, with overall satisfaction scores being Storz (4), ACMI (7.5) and Olympus (8.6), but disagreement in scores for Wolf (1.9 vs 5.3). CONCLUSIONS: Whilst there were considerable similarities in the objective assessment among the instruments, the user assessment showed qualitative variability. Thus it is important to try the different instruments before selecting one. Additional variables to consider include durability, cost and service/warranty, which vary considerably among instruments.

Equipment Design↗
PubMed2006

Comparison of 2 multiple-measurement infrared pupillometers to determine scotopic pupil diameter.

PURPOSE: To compare a monocular and a binocular multiple-measurement digital infrared pupillometers for measuring scotopic pupil diameter. SETTING: Department of Ophthalmology, Loma Linda University, Loma Linda, California, USA. METHODS: Scotopic pupil size was measured after 1 minute of dark adaptation in 42 eyes of 21 volunteers. Measurements were taken twice each with 2 multiple-measurement digital infrared pupillometers, the monocular pupillometer (Neuroptics, Inc.), and the binocular pupillometer (P2000D, Procyon, Ltd.) Intraclass correlation coefficients (ICC) and limits of agreement (LOA) were used to measure repeatability and agreement of measures with each instrument and between instruments. The Wilcoxon signed rank test was used to compare variability of measurements within each instrument. RESULTS: The mean scotopic pupil size was 4.79 mm +/- 0.95 (SD) with the Procyon and 4.86 +/- 0.93 mm with the Neuroptics. Repeatability and agreement tests for the Procyon measures showed the following: ICC, 0.954; 95% confidence interval (CI), 0.916-0.975; LOA, -0.60 to 0.56; range, 1.16. The Wilcoxon signed rank test of variability gave a Z score of -2.53 (P = .01, 2 tailed). The repeated measures testing with the Neuroptics pupillometer showed the following: ICC, 0.985; 95% CI, 0.972-0.992; LOA, -0.39 to 0.26; range, 0.64; Z score, -1.15 (P = .25, 2-tailed). Repeatability and agreement tests for measures between instruments showed the following: ICC, 0.954; 95% CI, 0.916-0.975; LOA, -0.60 to 0.50; range 1.11. CONCLUSIONS: There was a high repeatability and agreement in scotopic pupil diameter for repeated measures within each device and measurements between the devices. Differences in variability in scotopic pupil diameter evaluated by the Wilcoxon signed rank test were significant only with the Procyon pupillometer.

Aged↗
PubMed1992

Measuring ethanol in blood and breath for legal purposes: variability between laboratories and between breath-test instruments.

We determined the concentrations of ethanol in nearly simultaneous specimens of venous blood (BAC) and end-expired breath (BrAC) after healthy volunteers drank moderate amounts of alcohol. BAC was measured at two laboratories and BrAC was analyzed with two instruments (Intoxilyzer 5000) from the same manufacturer. The mean difference in BAC between laboratories was 0.0105 mg/g (SD 0.0219); 95% of the differences ranged from -0.0333 to 0.0543 mg/g. The mean difference in BrAC between instruments was 0.0153 mg/L (SD 0.0136), and 95% of the differences ranged from -0.0119 to 0.0425 mg/L. The coefficient of variation (CV) between laboratories was 2.9% compared with 4.5% between breath-test instruments. Venous BAC (y) and BrAC (x) were highly correlated (r = 0.978). However, when the Intoxilyzer instruments indicated that BrAC had reached zero, the actual BAC was 0.135 mg/g, according to the average forensic laboratory reports. The Intoxilyzer 5000 breath analyzers used in this study seem to have a constant analytical bias.

Adult↗
PubMed2001

Translating the short version of the Perinatal Grief Scale: process and challenges.

Non-English-speaking populations may be excluded from rigorous clinical research because of the lack of reliable and valid instrumentation to measure psychosocial variables. The purpose of this article is to describe the process and challenges when translating a research instrument. The process will be illustrated in the project of translating into Spanish the Short Version of the Perinatal Grief Scale, extensively studied in English-speaking, primarily Caucasian populations. Translation methods, errors, and tips are included. Tools cannot be used in transcultural research and practice without careful and accurate translation and subsequent psychometric evaluation, which are essential to generate credible and valid findings.

Abortion, Spontaneous↗
PubMed1998

Instrumentation for the remote monitoring of physiological and behavioral variables.

Few commercial products are available for investigators who wish to monitor multiple physiological and behavioral variables in unrestrained subjects. When telemetry is not practical, e.g., in studies of at-sea diving physiology, one of the only options is to design and build a custom data-logging instrument. This paper describes how a data logger was developed for the successful long-term monitoring of dive depth, swim speed, heart rate, water temperature, and multiple body temperatures from free-ranging northern elephant seals. The task was facilitated by using a commercially available single-board computer designed specifically for portable multichannel data acquisition and, where possible, off-the-shelf sensors/transducers available with integrated signal-conditioning circuits. A smaller data logger for monitoring the electrocardiogram, body temperature, and dive behavior of double-crested cormorants is also described to illustrate the flexibility and simplicity of this approach. Although it is customized for diving animals, with incorporation of the appropriate sensors the basic design should be applicable to studies of comparative, environmental, or exercise physiology involving most medium-to-large animals, including humans.

Animals↗
PubMed1981

Predicting adaptive functioning among mentally ill persons in community settings.

Attempts to improve instrumental role performance among mentally ill persons have traditionally focused on the modification of individual level variables. Recent interest in environmental-behavioral linkages, however, has led to attempt to isolate environmental variables which are both readily manipulable and significantly related to improved instrumental role performance. The present study examines the impact of a variety of individual, residential, and community variables on instrumental role performance using multiple regression analysis. The 10 variables in the equation had a multiple r of .77 with total score on the Residential portion of the Adaptive Functioning Index, indicating that they account for 60% of the variance in scores. Individual level variables account for 3% of the variance, while environmental variables, primarily those related to normalization account for 57% of the variance. The data suggest that environmental normalization may be an effective technology as well as an ideology.

Adaptation, Psychological↗
PubMed1998

Sources and determinants of social support for caregivers of persons with AIDS.

This study examines the determinants of social support among a sample of 642 caregivers of persons with AIDS living in San Francisco and Los Angeles. Respondents include both traditional family caregivers (mothers, spouses, other relatives) and non-traditional caregivers (friends, homosexual partners). Multiple regression analyses are conducted to assess the independent effects of six sets of variables on emotional and instrumental support: social-structural factors (age, education, employment status), caregiver's relationship to the person with AIDS, situational variables (caregiver's HIV status, patient's functional disability, interpersonal conflict), social network factors (contact with family, contact with friends, community integration), personal resources (mastery, caregiving competence), and use of formal community services (patient-directed services, caregiver-directed services). A number of factors and conditions appear to be relevant for caregiver support. For example, results indicate that network factors, including frequency of contact, conflict, and community integration, are importantly related to caregivers' perceptions of emotional support. There is also a trend suggesting lower emotional support among traditional family caregivers, relative to nonfamily caregivers, within gender categories. With respect to instrumental assistance with caregiving, factors that place greater demands and time constraints on caregivers, such as being employed and caring for an AIDS patient with greater functional limitations, appear to increase the level of informal instrumental support the caregiver receives. Partners and spouses, however, receive significantly lower instrumental assistance, independent of other factors. Implications of the findings are discussed.

Acquired Immunodeficiency Syndrome↗
PubMed2004

[Correlations between retinal thickness analyzer (RTA) and confocal scanning laser tomography (HRT) in optic disc analysis].

OBJECTIVES: To determine if the measures obtained in an optic disc study using the retinal thickness analyzer (RTA) can be adequately correlated with values provided by the confocal scanning laser Heidelberg Retina Tomograph (HRT). METHODS: We analyzed 20 eyes of 20 normal subjects. The contours of the optic disc were drawn by a single operator using both instruments. The data compared were the values of 10 variables denoted in the same way by each instrument and these provided information on disc and cup morphology. RESULTS: Of the 10 variables, only the following three showed clear correlation between the two instruments: maximum cup depth (r=0.926, p=0.001), mean cup depth (r=0.857, p=0.001) and cup shape measure (CSM, r=0.672, p=0.002). The correlation shown by the remaining variables ranged from 0.001 (cup area) and 0.488 (cup volume). CONCLUSIONS: The variables showing best correlation between instruments were those providing information on cup morphology. Operator subjectivity when drawing the disc contour using each device could account for the lower incidence of correlation of the other variables examined.

Adult↗