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Results for “Pretesting”

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PubMed2005

A hybrid qualitative method for pretesting questionnaires: the example of a questionnaire to caregivers of Alzheimer disease patients.

A hybrid method based on cognitive interviewing and consensus panels was developed to pretest a questionnaire for caregivers of persons with Alzheimer disease (AD). The objective of the questionnaire was to elicit caregivers' attitudes and opinions on the use of medications to treat the disease. Thirty-one caregivers were divided into five pretest groups, within which each participant was asked to comment on questionnaire wording and design. The comments from participants in the first three groups were used to revise the questionnaire, and the revised version was given to participants in the remaining two groups. Overall, 81% (118/146) of the participants' comments were implemented. The number of comments made in the last two groups decreased relative to the number of comments made in the first three groups. The hybrid method enhanced the user-friendliness of the questionnaire and can serve as an alternative to common ad hoc pretest approaches that have little basis in theory.

Adult↗

PubMed2000

Relation between exercise-induced ventricular arrhythmias and myocardial perfusion abnormalities in patients with intermediate pretest probability of coronary artery disease.

The significance of exercise-induced ventricular arrhythmias (VAs) is largely dependent on the clinical characteristics of the studied population. The relation between exercise-induced VAs and myocardial perfusion abnormalities has not yet been evaluated in a homogeneous patient population with intermediate probability of coronary artery disease (CAD). We studied 302 patients (mean age 54+/-9 years, 152 men and 150 women) with intermediate pretest probability of CAD (range=0.25-0.80, mean=0.43+/-0.20) by upright bicycle exercise stress test in conjunction with technetium-99m single-photon emission tomography (SPET) imaging. Exercise-induced VAs (frequent or complex premature ventricular contractions or ventricular tachycardia) occurred in 65 patients (22%). No significant difference was found between patients with and patient without VAs regarding the pretest probability of CAD (0.45+/-0.21 vs 0.43+/-0.20). Patients with exercise-induced VAs had a higher prevalence of perfusion abnormalities (52% vs 26%, P=0.002) and ischaemic electrocardiographic changes (31% vs 16%, P<0.05) compared to patients without VAs. A higher prevalence of perfusion abnormalities in patients with VAs was observed in both men (67% vs 35%, P<0.01) and women (38% vs 16%, P<0.05). However, the positive predictive value of exercise-induced VAs for the presence of myocardial perfusion abnormalities was higher in men than in women (67% vs 38%, P<0.05). The presence of abnormal myocardial perfusion was the only independent predictor of exercise-induced VAs (OR 2.2; 95% CI, 1.2-4.2) by multivariate analysis of clinical and stress test variables. It is concluded that in patients with intermediate pretest probability of CAD, exercise-induced VAs are predictive of a higher prevalence of myocardial perfusion abnormalities in both men and women. However, the positive predictive value of exercise-induced VAs for perfusion abnormalities is higher in men. Because of the underestimation of ischaemia by electrocardiographic changes, exercise-induced VAs should be interpreted as a marker of a higher probability of CAD.

Coronary Angiography↗

PubMedDate not supplied

Effect of posttraining and pretest beta-endorphin and ACTH administration in normal and protein malnourished rats.

Rats were submitted to a normal (25% casein) or a low protein diet (8% casein) from the day of birth until the age of 110 to 120 days. Hypothalamic beta-endorphin-like immunoreactivity was lower in the animals raised and maintained with the low protein diet, and, in addition, it did not respond to training in a step-down inhibitory avoidance task with or without footshock with a depletion, as was the case with the normal diet animals. In the animals submitted to the normal protein diet posttraining ACTH (0.2 micrograms/kg) and beta-endorphin (1.0 micrograms/kg) caused retrograde amnesia of a step-down inhibitory avoidance task, and pretest administration of these substances had no effect of its own, but was able to reverse the amnesia induced by their previous posttraining administration. In the animals submitted to the low protein diet, results were similar except that pretest beta-endorphin caused amnesia on its own. On the basis of previous findings which suggest that pretest actions of ACTH and beta-endorphin depend on their endogenous release at the time of training, the present results are compatible with a malfunction of the brain beta-endorphin system in the undernourished animals.

Adrenocorticotropic Hormone↗

PubMed2004

Applying evidence-based health care to musculoskeletal patients as an educational strategy for chiropractic interns (a one-group pretest-posttest study).

OBJECTIVE: To describe and measure the effectiveness of a problem-based educational strategy for teaching evidence-based health care (EBHC) to chiropractic interns, which focused on the development and appraisal of answerable clinical questions using actual musculoskeletal patients. METHODS: A 1-group pretest-posttest design (simple panel design) with investigator-blinded survey administration was used to measure effectiveness of educational activities using adult learning theory with a study population of interns (n=31) at a chiropractic college (Los Angeles College of Chiropractic, Southern California University of Health Sciences [LACC/SCUHS]) teaching clinic. Activities included 2 workshops on constructing clinical questions and critical appraisal of published research and independent patient-based EBHC assignments. A qualitative self-assessment survey was administered before and after a 6-week period of EBHC activities to measure their effectiveness. Sign tests and paired t tests were utilized to determine P values for significant difference of score results. RESULTS: Eighty-one percent of subjects completed the pretest-posttest surveys. All survey item responses showed an average increase in subjects' self-rating of skills and attitudes from pretest to posttest. There were statistically significant differences in interns' self-assessed ability to construct an answerable clinical question and appraise research articles and apply them to patient management, as well as their rating of importance of EBHC in patient decision making. CONCLUSIONS: The results of this study suggest that having chiropractic interns apply EBHC to actual musculoskeletal patients along with attending EBHC workshops had a positive impact on interns' perceived ability to practice EBHC.

Adult↗

PubMed1999

Comparison of the Diamond-Forrester method and a new score to estimate the pretest probability of coronary disease before exercise testing.

OBJECTIVE: We compared the Diamond-Forrester (DF) tabular method to assess pretest probability of coronary artery disease to a new scoring method (NS). METHODS: We evaluated 544 patients with suspected coronary disease who underwent both exercise electrocardiography and coronary angiography. The prevalence of any coronary artery disease (CAD) (>/=1 vessel with a >/=50% stenosis) within low, intermediate, and high pretest probability groups defined by the 2 methods was compared. The DF method used age, sex, and symptoms. The NS used those 3 factors plus 7 other risk factors. RESULTS: Overall prevalence of CAD was 41%. We compared the respective prevalence of CAD within pretest probability groups. Low probability: DF 27% versus NS 17% (P <.03); intermediate probability: DF 42% versus NS 47%; high probability: DF 70% versus NS 72%. We evaluated results separately in men and women. In women, no significant differences were found. However, in men, a significant difference in the low probability group was found (DF 47% versus NS 22%; P <.03). When the 47 asymptomatic patients were removed from the analysis, there were no differences between the 2 methods. Men: low probability, DF 17% versus NS 21%; intermediate probability, DF 45% versus NS 49%; high probability, DF 67% versus NS 72%. Women: low probability, DF 17% versus NS 15%; intermediate probability, DF 38% versus NS 27%; high probability, DF 83% versus NS 70%. CONCLUSION: In symptomatic patients, the accuracy of the 2 methods was the same. In asymptomatic patients, further evaluation in larger populations will be needed.

Coronary Angiography↗

PubMed2001

Exercise echocardiography for the prognostic stratification of patients with low pretest probability of coronary artery disease.

PURPOSE: The aim of this study was to determine whether exercise echocardiography provides incremental data for risk stratification of patients with a low pretest probability of coronary artery disease. PATIENTS AND METHODS: The study included patients referred for exercise echocardiography whose probability of coronary artery disease was 25% or less. We calculated an exercise wall motion score index (on a 1-5 scale), an indicator of the extent and severity of exercise-induced abnormalities. The primary outcomes of the study were subsequent cardiac events (cardiac death and nonfatal myocardial infarction). RESULTS: We studied 571 men and 1047 women; their mean (+/- SD) age was 55 +/- 13 years. During a median follow-up of 3 years, there were 19 cardiac events (6 cardiac deaths and 13 nonfatal myocardial infarctions); an additional 37 patients underwent coronary revascularization. In a multivariate analysis of clinical, exercise electrocardiographic, and echocardiographic parameters, exercise wall motion score index (hazard ratio [HR] = 2.1 per 0.5 units; 95% confidence interval [CI]: 1.3 to 3.4), and age (HR = 2.0 per decade; 95% CI: 1.2-2.8) were independently associated with the risk of cardiac events. Although exercise echocardiographic variables contributed significantly (P = 0.01) to a model of the risk of adverse events, only 9 (47%) of the 19 patients with cardiac events were identified by an abnormal exercise echocardiogram. CONCLUSION: Among patients with low pretest probability of coronary artery disease by clinical criteria, exercise echocardiography identifies some, but not all, patients at risk of future events. Because of the low event rate, routine application of exercise echocardiography in a patient with a low pretest probability does not appear to be cost-effective and therefore cannot be recommended.

Adult↗

PubMed2002

[Diagnostic value of D-dimer in patients with a low pretest probability of deep venous thrombosis of lower extremities].

BACKGROUND: We aimed to assess the accuracy of a diagnostic strategy including broth clinical assessment and determination of D-dimer (DD) in patients with clinically suspicion of low pretest probability of deep venous thrombosis (DVT). METHOD: 149 outpatients (mean age 69; SD 16) with clinically suspected proximal DVT attending our Emergency Department and classified as low pretest probability were included in an observational prospective study. In patients with a DD (STA Liatest D-Di, Diagnostica Stago, Asnières sur Seine, France) concentration below the cut-off value (0.4 ng/ml) the diagnosis of DVT was readily ruled out, whereas those individuals with a positive DD result underwent compression Doppler venous ultrasound. A 3-month clinical follow-up was carried out in those patients in whom a diagnosis of DVT was initially excluded. RESULTS: Only 2 cases of DVT were confirmed (prevalence 1.3%; CI 95%, 0.2-5.3). In 47.6% of cases, a DD negativity ruled out the diagnosis of DVT. The rate of negative DD results was significantly lower in patients below 70 years of age as compared to older patients (73.6 versus 33.3%) (p < 0.001). Sensitivity, specificity, positive predictive value and negative predictive value of DD in our series were 100% (CI 95%,19.7-95.1), 48.3% (CI 95%, 40.0-56.7), 2.6% (CI 95%, 0.4-9.8) and 100% (CI 95%, 93.6-99.8) respectively, the latter being similar in the two age groups. No case of DVT was diagnosed during the follow-up period. CONCLUSIONS: In patients with a low pretest probability of DVT a negative DD result reliably and safely rules out such diagnosis. However, the diagnostic value of DD is lower in elderly patients (>= 70 years of age) due to a lower rate of negative results in these individuals.

Aged↗

PubMed2002

Diagnostic value of d-dimer in patients with a moderate pretest probability of deep venous thrombosis.

The negative predictive value (NPV) of d-dimer (DD) for the exclusion of venous thromboembolism is, overall, high and tends to increase as clinical pretest probability decreases. We have assessed the accuracy of a diagnostic protocol including clinical evaluation and DD in 134 outpatients presenting with a moderate pretest probability of proximal deep venous thrombosis (DVT). In these patients, a negative DD value safely excluded DVT (NPV 100%, 95% CI 85-100) In our experience, these results are equivalent to those found for low-pretest probability patients and therefore the same diagnostic strategy can be used for both risk groups.

Aged↗

PubMed2003

Cognitive interviewing: verbal data in the design and pretesting of questionnaires.

PURPOSE: The purpose of this paper is to discuss problems that occur in questionnaire responses and how cognitive interviewing can be used to identify problematic questions prior to using the questionnaire in the field. BACKGROUND: Questionnaire design involves developing wording that is clear, unambiguous and permits respondents successfully to answer the question that is asked. However, a number of problems in relation to respondents' understanding and successfully completing questionnaires have been identified. Cognitive interviewing, an amalgamation of cognitive psychology and survey methodology, has been developed to identify problematic questions that may elicit response error. The overall aim is to use cognitive theory to understand how respondents perceive and interpret questions and to identify potential problems that may arise in prospective survey questionnaires. METHODS: A literature review is used to examine the process of questionnaire design and how cognitive interviewing can be used to reduce sampling error and increase questionnaire response rates. FINDINGS: Cognitive interviewing involves interviewers asking survey respondents to think out loud as they go through a survey questionnaire and tell them everything they are thinking. This allows understanding of the questionnaire from the respondents' perspective rather than that of the researchers. Cognitive interviews have been used in a number of areas in health care research to pretest and validate questionnaires and to ensure high response rates. Interviewing has been found to be highly effective in developing questionnaires for age specific groups (children and adolescents) and in ascertaining respondents' understanding in health surveys prior to distribution. However, cognitive interviews have been criticized for being overly subjective and artificial. CONCLUSION: Cognitive interviews are a positive addition to current methods of pretesting questionnaires prior to distribution to the sample. They are most valuable in pretesting questions that are complex, where questions are sensitive and intrusive and for specific groups for whom questionnaire completion may pose particular difficulties.

Cognitive Science↗

PubMed2003

Could our pretest probabilities become evidence based? A prospective survey of hospital practice.

OBJECTIVE: We sought to measure the proportion of patients on our clinical service who presented with clinical problems for which research evidence was available to inform estimates of pretest probability. We also aimed to discern whether any of this evidence was of sufficient quality that we would want to use it for clinical decision making. DESIGN: Prospective, consecutive case series and literature survey. SETTING: Inpatient medical service of a university-affiliated Veterans' Affairs hospital in south Texas. PATIENTS: Patients admitted during the 3 study months for diagnostic evaluation. MEASUREMENTS: Patients' active clinical problems were identified prospectively and recorded at the time of discharge, transfer, or death. We electronically searched medline and hand-searched bibliographies to find citations that reported research evidence about the frequency of underlying diseases that cause these clinical problems. We critically appraised selected citations and ranked them on a hierarchy of evidence. RESULTS: We admitted 122 patients for diagnostic evaluation, in whom we identified 45 different principal clinical problems. For 35 of the 45 problems (78%; 95% confidence interval [95% CI], 66% to 90%), we found citations that qualified as disease probability evidence. Thus, 111 of our 122 patients (91%; 95% CI, 86% to 96%) had clinical problems for which evidence was available in the medical literature. CONCLUSIONS: During 3 months on our hospital medicine service, almost all of the patients admitted for diagnostic evaluation had clinical problems for which evidence is available to guide our estimates of pretest probability. If confirmed by others, these data suggest that clinicians' pretest probabilities could become evidence based.

Decision Support Techniques↗

PubMed2006

Clinical value of MDCT in the diagnosis of coronary artery disease in patients with a low pretest likelihood of significant disease.

OBJECTIVE: The aim of this study was to evaluate the clinical value of MDCT in the diagnosis of coronary artery disease in a population having a low pretest likelihood of significant disease. SUBJECTS AND METHODS: Sixty-four patients with suspected coronary artery disease and a low pretest likelihood of significant disease according to the criteria of the American Heart Association underwent both MDCT of the heart and quantitative conventional coronary angiography (QCA). MDCT examinations were performed on a 16-MDCT scanner. CT data sets were evaluated on a per-patient basis and a per-segment basis and were classified as indicating no disease, nonsignificant disease (stenoses </= 50%), or significant disease (stenoses > 50%). Sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) of 16-MDCT in the detection or exclusion of significant and nonsignificant coronary artery disease were evaluated on both per-patient and per-segment bases. RESULTS: Regarding the success rate of 16-MDCT, 94% (60/64) of patients and 92% (388/420) of vessel segments were of sufficient quality for diagnosis. In the remaining 60 patients evaluated, QCA revealed significant coronary artery disease, nonsignificant disease, and no disease in 8.3% (5/60), 75.0% (45/60), and 16.7% (10/60) of cases, respectively, on a per-patient basis, and in 1.3% (5/388), 23.2% (90/388), and 75.5% (293/388) of cases, respectively, on a per-segment basis. The sensitivity, specificity, NPV, and PPV of 16-MDCT for the detection of significant coronary artery disease were 80.0%, 94.5%, 98.1%, and 57.1%, respectively, on a per-patient basis, and 80.0%, 99.2%, 99.7%, and 57.1% on a per-segment basis. CONCLUSION: In a population having a low pretest likelihood of significant coronary artery disease, 16-MDCT shows a moderate to high sensitivity and high NPV for the detection or exclusion of significant disease, but has a somewhat reduced PPV compared with QCA.

Adult↗

PubMed2003

Pretest-posttest designs and measurement of change.

The article examines issues involved in comparing groups and measuring change with pretest and posttest data. Different pretest-posttest designs are presented in a manner that can help rehabilitation professionals to better understand and determine effects resulting from selected interventions. The reliability of gain scores in pretest-posttest measurement is also discussed in the context of rehabilitation research and practice.

Analysis of Variance↗

PubMed1998

Psychosocial and educational outcomes associated with home- and clinic-based pretest education and cystic fibrosis carrier testing among a population of at-risk relatives.

We report on the psychosocial and knowledge outcomes of two different approaches to cystic fibrosis (CF) gene pretest education and carrier testing offered to 288 proactively recruited first-, second-, and third-degree relatives of people with CF. One group received pretest education and gene testing in a clinical setting from a certified genetic counselor. The other group received pretest education in their homes from a specially prepared pamphlet and were asked to send in a buccal cell sample for genotyping. No statistically significant differences between groups were noted on measures of CF knowledge, anxiety, and positive or negative affect, either while waiting for their test results or within a few weeks after they had learned their results. At both measurement points, participants who had received home education and testing reported that the testing was more convenient, but that they had received less information than they would have liked, and they were more likely to report being confused by the testing, although their level of CF knowledge was comparable to that of people who had been seen by a genetic counselor. In light of the increasing interest in home-based medical testing of all kinds, this study suggests that CF carrier testing in the home warrants further consideration as one possible approach to facilitating access to testing.

Adolescent↗

PubMedDate not supplied

Modeling the concentration of ethanol in the exhaled breath following pretest breathing maneuvers.

A previously developed mathematical model that describes the relationship between blood alcohol (ethanol) concentration and the concentration of alcohol in the exhaled breath at end-exhalation (BrAC) has been used to quantitate the effect of pretest breathing conditions on BrAC. The model was first used to "condition" the airways with different breathing maneuvers prior to simulating a single exhalation maneuver, the maneuver used in standard breath alcohol testing. On inspiration, the alcohol in the air reaches local equilibrium with the alcohol in the bronchial capillary bed prior to entering the alveolar region. On expiration, approximately 50% of the alcohol absorbed on inspiration is desorbed back to the airways. BrAC correlates with the amount of alcohol that is desorbed to the airways. The six pretest breathing conditions and the percent change in BrAC relative to the control maneuver were: hyperventilation (-4.4%), hypoventilation (3.7%), hot-humid air (-2.9%), hot-dry air (0.66%), cold-humid air (0.13%), and cold-dry air (0.53%). The mechanism underlying these responses is not due to changes in breath temperature, but, rather to changes in the axial profile of alcohol content in the mucous lining of the airways.

Air↗

PubMed2005

Inverse dose effect of pretest dietary lactose intake on breath hydrogen results and symptoms in lactase nonpersistent subjects.

The aim of this study was to determine a relationship between pretest intake of lactose and outcome of lactose breath hydrogen test. Patients presented at a testing laboratory participated in the study. A 3-hour breath hydrogen, 50-g lactose challenge was carried out. Results were tabulated and patients completed a 3-day recall diet questionnaire. Daily lactose intake was independently calculated and was associated with breath hydrogen and total symptom score. Statistical analysis used Spearman's correlation, Mann-Whitney U-test and chi2 or Fisher exact test. Of 118 patients, 50% were lactose maldigesters. In these patients, measured breath hydrogen and symptom scores were significantly higher in the lowest intake group (< 5 g/d) than in the highest intake group (> 20 g/d) (P < .05). In the presumed lactose digesters, 59% experienced some symptoms during testing for unclear reasons. Pretest dietary intake of lactose inversely affects results of breath hydrogen.

Adolescent↗

PubMed1993

Prognostic value of dobutamine echocardiography in patients with high pretest likelihood of coronary artery disease.

To examine the value of transient regional asynergy on dobutamine stress echocardiography as a noninvasive predictor of future cardiac events, 51 symptomatic patients (aged 54 +/- 9 years) with suspected coronary artery disease (CAD) were studied using an incremental regimen of 5, 10, 15 and 20 micrograms/kg/min. Pretest likelihood of CAD was (mean +/- standard error of the percentage) 79.7 +/- 5.6% before and 83.4 +/- 5.2% after exercise electrocardiography using probability analysis based on age, sex and symptoms. Two-dimensional images were analyzed with reference to an 11-segment model and gave good interrater agreement. During 24 +/- 4 months (range 19 to 32) of follow-up, 23 patients had events (1 myocardial infarction, 9 unstable angina, 10 coronary bypass surgery, 3 coronary angioplasty) and 28 were event free. Age, proportion with baseline asynergy and both pretest echocardiographic ejection fraction and its response to dobutamine were similar in these 2 groups (all p = not significant). Transient asynergy was seen in 17 of 23 patients (74%) with and 8 of 28 patients (29%) without events (p < 0.01); 5 of 6 patients (83%) with involvement of 3 segments had events. Myocardial infarction or unstable angina occurred in 8 of 25 (32%) with a positive and 2 of 26 (8%) with a negative stress echocardiogram (p < 0.05). Both exercise duration (389 +/- 195 vs 517 +/- 237 seconds, p < 0.05) and time to diagnostic ST-segment shift (291 +/- 192 vs 447 +/- 212 seconds, p = 0.05) were shorter in those with inducible asynergy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1983

The repeated pretest-posttest single-subject experiment: a new design for empirical clinical practice.

The logic of a new design for empirical clinical practice, the repeated pretest-posttest experiment, is described. This design is readily applicable by individual practitioners in the human services, possesses high internal validity, and presents minimal intrusiveness into the delivery of service. A single-case study is used to illustrate the application of the repeated pretest-posttest experiment in clinical research.

Adult↗

PubMed1975

Clinician bias: the effects of pretesting information on the evaluations of speech clinicians.

The purpose of this investigation was to determine if pretesting information has a biasing effect on the speech evaluations of student speech clinicians. A total of three groups of clinicians evaluated 10 speech characteristics of each of 17 recorded speech samples. The clinicians participated in two listening sessions. In the first (control) session, they evaluated the speech samples using a 4-point scale of defectiveness and were given no background information on the speakers. In the second (experimental) session, they were given fabricated case history information prior to their evaluations. Results of their ratings indicate that the pretesting information had a biasing effect on the clinicians' evaluations of the speech samples. Implications of these findings and suggestions for future inquiry are discussed.

Adolescent↗