Individual patient radiation dose tracking: Perceptions of radiographers in South Africa.

INTRODUCTION: Medical imaging examinations that make use of ionising radiation provide valuable information towards patient management. Literature suggests that there is a significant rise in the number of patient referrals for such examinations. The concept "individual patient radiation dose tracking" (IPRDT) is introduced to optimise radiation monitoring. Many countries across the globe explored and implemented methods to enhance and promote the justification and optimisation principles essential for patient radiation safety. In South Africa (SA), however, attention to IPRDT is limited. METHODS: A qualitative research design was employed. Radiographers in the Western Cape Province of SA were purposefully sampled for participation in one-on-one, semi-structured interviews. Thematic analysis was applied to the transcribed interview data. RESULTS: This paper presents a theme developed from the radiographer cohort of ten (10) participants. The theme: the need for creating awareness and implementing legislative support structures, was developed from the data, with the following supporting subthemes: 1) stakeholder awareness and 'buy-in' 2) continuous professional development and 3) mandated practice. CONCLUSION: This study provides findings that are of value for patient radiation safety in SA by giving a voice to local stakeholders. Other countries that are conducting similar research investigations toward the integration of an IPRDT model, method, or framework, may also benefit from these findings. IMPLICATIONS FOR PRACTICE: The effective integration of IPRDT into the clinical environment requires unison amongst the relevant stakeholders and clarity on the various professionals' roles and responsibilities. The findings of this study furthermore suggest the involvement of regulatory organisations for the provision of a mandated form of practice at national and international levels.

One in four people may develop symptomatic hip osteoarthritis in his or her lifetime.

OBJECTIVE: To estimate the lifetime risk of symptomatic hip osteoarthritis (OA). DESIGN: We analyzed data from the Johnston County Osteoarthritis Project [a longitudinal population-based study of OA in North Carolina, United States (n=3068)]. The weighted baseline sample comprised 18% blacks and 54% women, and the mean age was 63 years (range=45-93). Symptomatic hip OA was defined as a Kellgren-Lawrence (K-L) radiographic score of ≥ 2 (anterior-posterior pelvis X-rays) and pain, aching or stiffness on most days, or groin pain, in the same hip. Lifetime risk, defined as the proportion who developed symptomatic hip OA in at least one hip by age 85, among people who live to age 85, was modeled using logistic regression with repeated measures (through generalized estimating equations). RESULTS: Lifetime risk of symptomatic hip OA was 25.3% [95% confidence interval (CI)=21.3-29.3]. Lifetime risk was similar by sex, race, highest educational attainment, and hip injury history. We studied lifetime risk by body mass index (BMI) in three forms: at age 18; at baseline and follow-up; and at age 18, baseline and follow-up and found no differences in estimates. CONCLUSION: The burden of symptomatic hip OA is substantial with one in four people developing this condition by age 85. The similar race-specific estimates suggest that racial disparities in total hip replacements are not attributable to differences in disease occurrence. Despite increasing evidence that obesity predicts an increased risk of both hip OA and joint replacement, we found no association between BMI and lifetime risk.

Gender differences in survival in advanced heart failure. Insights from the FIRST study.

BACKGROUND: Previous natural history studies in broad populations of heart failure patients have associated female gender with improved survival, particularly in patients with a nonischemic etiology of ventricular dysfunction. This study investigates whether a similar survival advantage for women would be evident among patients with advanced heart failure. METHODS AND RESULTS: The study analysis is based on the Flolan International Randomized Survival Trial (FIRST) study which enrolled 471 patients (359 men and 112 women) who had evidence of end-stage heart failure with marked symptoms (60% NYHA class IV) and severe left ventricular dysfunction (left ventricular ejection fraction 18+/-4.9%). A Cox proportional-hazards model, adjusted for age, gender, 6-minute walk, dobutamine use at randomization, mean pulmonary artery blood pressure, and treatment assignment, showed a significant association between female gender and better survival (relative risk of death for men versus women was 2.18, 95% CI 1.39 to 3.41; P<0.001). Although formal interaction testing was negative (P=0.275), among patients with a nonischemic etiology of heart failure, the relative risk of death for men versus women was 3.08 (95% CI 1.56 to 6.09, P=0.001), whereas among those with ischemic heart disease, the relative risk of death for men versus women was 1.64 (95% CI 0.87 to 3.09, P=0.127). CONCLUSIONS: Women with advanced heart failure appear to have better survival than men. Subgroup analysis suggests this finding is strongest among patients with a nonischemic etiology of heart failure.

Acetaminophen overdose. 662 cases with evaluation of oral acetylcysteine treatment.

Six hundred sixty-two consecutive patients with acetaminophen overdoses were evaluated. Those at risk on the basis of their acetaminophen blood levels, as plotted on the study nomogram, were treated with oral acetylcysteine. Statistically significant differences in severity of hepatic toxicity were observed between patients treated within 16 hours after ingestion and those treated between 16 and 24 hours after ingestion. No deaths occurred among patients treated within 24 hours of ingestion, except for one patient who was an alleged gunshot homicide. Seven percent of patients with plasma acetaminophen levels in the potentially toxic range and treated with acetylcysteine within ten hours of ingestion showed transient SGOT level elevations, whereas 29% of those treated between ten and 16 hours after ingestion and 62% of those treated between 16 and 24 hours after ingestion showed such transient toxicity. No consistent difference in hepatotoxicity could be demonstrated between those patients with a history of chronic alcohol use and those patients with no history of chronic alcohol use. Acute alcohol use resulted in less severe toxic reactions than in those patients without acute alcohol use.

A randomized controlled trial of the effects of three antihypertensive agents on blood pressure control and quality of life in older women.

We conducted a multicenter, randomized, double-blind, parallel group trial to compare the impact of titrated doses of atenolol (50 to 100 mg once a day), enalapril (5 to 20 mg once a day), and diltiazem (sustained release) (60 to 180 mg twice a day) on blood pressure and quality of life in older hypertensive women. Two hundred forty-two patients were randomized. Dose titration was completed by week 4 after randomization, and the maintenance phase was completed at week 16. Diltiazem (sustained release) demonstrated greater diastolic blood pressure lowering at both weeks 8 and 16 by an intent-to-treat analysis. At week 16, diltiazem changed diastolic blood pressure -13.7 +/- 0.7 mm Hg compared with -10.8 +/- 1.1 mm Hg for atenolol, and -10.5 +/- 0.9 mm Hg for enalapril. Diltiazem also demonstrated greater lowering of systolic blood pressure at week 3, but these differences in systolic blood pressure had decreased by week 16. More patients were classified as treatment failures during the 16 weeks of the trial for atenolol (15%) than for diltiazem (2.5%), while the treatment failure rate was intermediate with enalapril (8%). Total rates of adverse events were equivalent across the three treatment arms. There were few significant differences in the impact of the three treatments on mean scores of quality-of-life measures at week 16. There was a trend for atenolol to have somewhat worse quality-of-life scores, but none of these differences were statistically significant. In conclusion, all three treatment regimens were effective in lowering diastolic blood pressure without significant differences in rates of adverse events or deleterious effects on quality of life.

Correlates of cortical bone mass among premenopausal and postmenopausal Japanese women.

Few studies have examined the multifactorial risk factors of bone mass in Asian populations. This cross-sectional study was designed to explore relationships between bone mass and environmental variables, including dietary and life-style factors, in Japanese women living in Japan. A total of 178 Japanese women completed the study: 89 premenopausal, ages 35-40, and 89 postmenopausal, ages 55-60. Midradial bone mineral content (MBMC) and bone mineral content per unit area, referred to as bone density (MBMD), were measured using single-photon absorptiometry. The major results of this investigation were the following: (1) The postmenopausal women differed significantly from the premenopausal women in having lower radial bone parameters, lower mean height, later age of menarche, and higher dietary intakes of carbohydrates, vegetables, and milk with a lower intake of caffeine. (2) Current protein intake was a positive correlate of MBMC in both groups. (3) Intake of vegetables (leafy green, yellow, orange, and white) and current milk intake were positively associated with MBMC in the postmenopausal women. (4) For the premenopausal women, irregular menstrual cycles was a negative correlate of MBMC, and for the postmenopausal women, years of menopause was negatively associated with MBMC and MBMD. Longitudinal studies are needed to establish more conclusively associations among diet, life-style, and reproductive history and bone mass of Japanese women.

Potential anticoagulant drug interactions in ambulatory patients.

Computer-generated prescription drug purchase records for ambulatory patients receiving oral anticoagulants (OAC) were studied for concomitant use of other drugs which have been reported to induce clinically significant interactions. One third of 479 patients taking OAC were exposed to a potentially interacting drug at some time during this 6-month period. The percentage of patients with drug interaction exposure correlated directly with total drug use (p less than 0.0005). There were no significant differences when interaction exposure rates were compared in the cases of single : multiple pharmacy and single : multiple physician-patient groups. Warfarin was the most common anticoagulant (greater than 95%) and barbiturates the most common interacting drug.

Influence of range of renal function and liver disease on predictability of creatinine clearance.

Several formulas for predicting creatinine clearance (Ccr) are used for adjusting drug dosages but limited data are available on their accuracy in patients with significant renal impairment or concurrent disease. We measured 144 Ccr in 103 patients and compared results using four predictive methods. Of nine common diseases in these patients, liver disease was associated with a large (p less than 0.02) prediction error (overprediction). After data from eight patients with liver disease were removed, there was good overall correlation between predicted and measured Ccr (r2 = 0.91 for each method) but only two of the methods (I and IV) were consistently accurate in all ranges of renal function. Methods for predicting Ccr should not be used in patients with liver disease.

Ultrasonic assessment of body composition in obese adults: overcoming the limitations of the skinfold caliper.

Previous research in this laboratory, using relatively lean males, indicated that the skinfold caliper and ultrasound techniques gave similar predictions of body density. The present study compared caliper with ultrasound measurements in predicting body density of 44 white, obese, free-living adult volunteers of both sexes. Subcutaneous-fat thickness was measured at six body sites with a Lange caliper and an ADR 2130 ultrasound scanner. By hydrostatic weighing, mean (+/- SD) body density was 1.01 g/mL (+/- 0.02) and percentage body fat, 41.7% (+/- 7.8). The best predictors of body density were the thigh and biceps sites with ultrasound (r = 0.820) and the triceps site with the calipers (r = 0.633). Further, ultrasound proved to be superior to the caliper technique in measuring subcutaneous fat of obese persons.

Maintenance therapy with sucralfate in duodenal ulcer: genuine prevention or accelerated healing of ulcer recurrence?

We sought to compare the efficacy of sucralfate to placebo for the prevention of duodenal ulcer recurrence and to determine that the efficacy of sucralfate was due to a true reduction in ulcer prevalence and not due to secondary effects such as analgesic activity or accelerated healing. This was a double-blind, randomized, placebo-controlled, parallel groups, multicenter clinical study with 254 patients. All patients had a past history of at least two duodenal ulcers with at least one ulcer diagnosed by endoscopic examination 3 months or less before the start of the study. Complete ulcer healing without erosions was required to enter the study. Sucralfate or placebo were dosed as a 1-g tablet twice a day for 4 months, or until ulcer recurrence. Endoscopic examinations once a month and when symptoms developed determined the presence or absence of duodenal ulcers. If a patient developed an ulcer between monthly scheduled visits, the patient was dosed with a 1-g sucralfate tablet twice a day until the next scheduled visit. Statistical analyses of the results determined the efficacy of sucralfate compared with placebo for preventing duodenal ulcer recurrence. Comparisons of therapeutic agents for preventing duodenal ulcers have usually been made by testing for statistical differences in the cumulative rates for all ulcers developed during a follow-up period, regardless of the time of detection. Statistical experts at the United States Food and Drug Administration (FDA) and on the FDA Advisory Panel expressed doubts about clinical study results based on this type of analysis. They suggested three possible mechanisms for reducing the number of observed ulcers: (a) analgesic effects, (b) accelerated healing, and (c) true ulcer prevention. Traditional ulcer analysis could miss recurring ulcers due to an analgesic effect or accelerated healing. Point-prevalence analysis could miss recurring ulcers due to accelerated healing between endoscopic examinations. Maximum ulcer analyses, a novel statistical method, eliminated analgesic effects by regularly scheduled endoscopies and accelerated healing of recurring ulcers by frequent endoscopies and an open-label phase. Maximum ulcer analysis reflects true ulcer recurrence and prevention. Sucralfate was significantly superior to placebo in reducing ulcer prevalence by all analyses. Significance (p less than 0.05) was found at months 3 and 4 for all analyses. All months were significant in the traditional analysis, months 2-4 in point-prevalence analysis, and months 3-4 in the maximal ulcer prevalence analysis. Sucralfate was shown to be effective for the prevention of duodenal ulcer recurrence by a true reduction in new ulcer development.

Sucralfate tablets 1 g twice a day for the prevention of duodenal ulcer recurrence.

Sucralfate 1 g twice daily was found to be significantly better than placebo for the prevention of duodenal ulcer recurrence. This was a double-blind, randomized, placebo-controlled, parallel groups study. A total of 254 patients with a history of two or more duodenal ulcers, the most recent event diagnosed within three months of study entry, were entered into the trial after healing was documented. Patients received sucralfate 1 g twice daily or placebo for four months, or until recurrence. Endoscopies and symptom assessments were scheduled monthly and at investigator discretion upon symptom development. Treatment groups were comparable with regard to number of patients, age, sex, smoking status, and ulcer history. Traditional ulcer prevalence and point prevalence analyses were performed. Traditional ulcer prevalence included all ulcers found at scheduled visits and interim recurrences. Point prevalence included only ulcers found at scheduled visits. In the traditional analysis, sucralfate was significantly better than placebo in reducing ulcer recurrence for all months of the study. The life table estimate of the cumulative percent with ulcer at four months was 42 percent for the sucralfate group and 63 percent for the placebo group (p = 0.002). At four months, there were 49 recurrences among 122 patients in the sucralfate group and 71 among 117 patients for the placebo group. In the point prevalence analysis, sucralfate was significantly better than placebo in reducing ulcer recurrence at Months 2 through 4. The life table estimate of the cumulative percent with ulcer at four months was 36 percent for the sucralfate group and 55 percent for the placebo group (p = 0.005). At four months, there were 38 recurrences among 114 patients in the sucralfate group and 54 among 104 patients for the placebo group. Both analyses demonstrated that sucralfate 1 g twice daily was significantly better than placebo for the prevention of duodenal ulcer recurrence. Symptom development was associated with recurrence in both treatment groups. Smoking was associated with a greater tendency to recur in placebo-treated patients only.

Interpretation of statistical methodology associated with maintenance trials.

Maintenance trials in ulcer disease provide a scientific framework through which the prophylactic performances of two or more therapies can be compared with respect to ulcer recurrence. For this purpose, a primary source of data is the endoscopic classification of patients at protocol-scheduled visits as well as at unscheduled visits. Several statistical issues are relevant to the analysis of this endoscopic information. First, the extent to which the respective patients have different data patterns for their ulcer recurrence status must be taken into account by actuarial methods that adjust for the length of follow-up time. Second, the role of multiple investigators requires careful attention when information is combined from them. A third issue is concerned with the assessment of the variation of ulcer recurrence experience across subgroups with respect to patient demographics, medical history, and baseline characteristics. Statistical methods can effectively address these issues so that the results of maintenance studies can be interpreted through estimates for ulcer recurrence rates. In this way, they can meaningfully support clinical conclusions about the performance of alternative therapies for maintaining the absence of ulcer disease over time.

Variability of spontaneous and exercise-induced ventricular arrhythmias in the absence and presence of treatment with acebutolol or quinidine.

A randomized double-blind crossover trial was undertaken in 20 volunteers to evaluate the effects of acebutolol and sustained release quinidine sulfate. The patients had an average of 10 or more premature ventricular complexes/hour on two 24 hour electrocardiographic recordings, or 10 or more/min during two cycle stress tests, or any number of complex forms of ventricular ectopic activity on either test. The 24 hour recordings yielded greater detection of complex forms than did stress tests and manifested similar relative variability in frequency of ventricular ectopic beats. The extent of variability from hour to hour within the 24 hour monitoring periods tended to have an increasing relation with frequency of ectopic beat activity regardless of the presence or absence of treatment. Within-patient variability among periods with equivalent treatment status also tended to have such an increasing relation with frequency of ectopic beat activity. About 35 percent of the variation was among subjects, 20 percent among months within subjects, 20 percent among days in months and 25 percent among hours in days. Acebutolol, 300 mg three times daily, produced effective beta receptor blockade and was better tolerated than sustained release quinidine sulfate in identical doses and had equal suppressant effects. The results of the variability studies provide guidelines for the design of adequate clinical trials testing suppressant interventions.

Prognostic value of exercise echocardiography in women in the community setting.

Treadmill stress echocardiography was performed in 1,136 women with known or suspected coronary artery disease whose clinical course was then evaluated a mean of 33 months later (range 12 to 60). The strongest predictor of an adverse outcome was the presence of a resting or an exercise-induced wall motion abnormality.

Effects of an ionic and nonionic contrast agent on von Willebrand factor assessed during coronary angiography.

This study shows an increase in von Willebrand factor antigen in blood collected from the coronary sinus shortly after coronary angiography with an ionic contrast agent (diatrizoate), but not a nonionic contrast agent (iohexol). These findings suggest that ionic contrast agents may cause more endothelial injury than nonionic contrast agents.

HIV seroprevalence in sexually transmitted disease clients in a low-prevalence southern state. Evidence of endemic sexual transmission.

We studied human immunodeficiency virus (HIV) seroprevalence and risk factors in 3052 clients attending three large public, sexually transmitted disease (STD) clinics in central North Carolina in mid-1988. Anonymous self-administered questionnaires linked to HIV serologies obtained by testing extra blood from syphilis serologies without personal identifiers showed the following characteristics of the respondents: 60% were men, 81% were black, the median age was 24 years, 5% were injecting drug users since 1978, 7% reported a history of syphilis, and 8% of men were homosexual or bisexual. HIV seropositivity was found in 76 subjects (2.5%), including 46% of the homosexual men, 25% of the bisexual men, 1.6% of the heterosexual men, and 0.6% of the women. Elevated HIV seroprevalence rates were found in subjects with a history of or seroreactivity for syphilis (HIV-positive rate of 53% in homosexual or bisexual men, 9% in heterosexual men, 3% in women) and with histories of gonorrhea (HIV-positive rate of 37% in homosexual or bisexual men, 2.6% in heterosexual men, 1% in women), and intercourse (41% in homosexual or bisexual men, 2% in women), prostitute contact (5% in heterosexual men), and sex with casual partners (2% in women). Even a state with a low incidence of acquired immunodeficiency syndrome can include subpopulations with a high HIV seroprevalence, apparently disseminated endemically in association with bacterial STDs.

Some applications of categorical data analysis to epidemiological studies.

Several examples of categorized data from epidemiological studies are analyzed to illustrate that more informative analysis than tests of independence can be performed by fitting models. All of the analyses fit into a unified conceptual framework that can be performed by weighted least squares. The methods presented show how to calculate point estimate of parameters, asymptotic variances, and asymptotically valid chi 2 tests. The examples presented are analysis of relative risks estimated from several 2 x 2 tables, analysis of selected features of life tables, construction of synthetic life tables from cross-sectional studies, and analysis of dose-response curves.

The MDS Cognition Scale: a valid instrument for identifying and staging nursing home residents with dementia using the minimum data set.

OBJECTIVE: We report the development and validation of an MDS-based cognitive index, the MDS Cognition Scale (MDS-COGS), by evaluating it against two popular dementia rating scales, the Global Deterioration Scale (GDS) and the Mini-Mental State Examination (MMSE). DESIGN: A Cross-sectional study. PARTICIPANTS: Two hundred nursing home residents. MEASUREMENTS: Each study participant was assessed on the GDS and the MMSE by trained medical students. At the same time, but independent of the medical students, a geriatric nurse completed the Minimum Data Set (MDS) instrument on each participant. MAIN RESULTS: The Cognitive Performance Scale (CPS), a categorical measure of cognition that uses MDS items, was compared with the GDS in 133 subjects, using a split-sample technique. The GDS was found to be more appropriate as a 4-stage than a 7-stage scale, with GDS stages 1-4 acting as a single stage. The CPS showed very poor percent agreement with GDS stages 5 and 7 (50% or less) and, therefore, was revised by adding other MDS predictors. The new instrument, designated MDS-COGS, is a 0-10 point scale generated from eight MDS cognitive items. The MDS-COGS was then validated against the 4-stage GDS and MMSE in the remaining 67 nursing home residents. Chance-corrected agreement (kappa) between the MDS-COGS and GDS in the 67 subjects was 0.80 (95% CI = 0.70, 0.88), and percent agreement with GDS stages 5 and 7 was 60% and 85%, respectively. The MDS-COGS was also demonstrated to be a valid measure of cognitive impairment as defined by the MMSE, with sensitivity, specificity, chance-corrected agreement (kappa), and area under the ROC curve, all above 0.80. CONCLUSIONS: The MDS Cognition Scale, the MDS-COGS, provides a valid measure of the presence and severity of cognitive impairment in nursing home residents using items from the Minimum Data Set.

Validation of the Minimum Data Set Cognitive Performance Scale: agreement with the Mini-Mental State Examination.

BACKGROUND: Almost all nursing homes in the United States are required by the 1987 Omnibus Budget Reconciliation Act to assess each resident's functional, medical, psychosocial, and cognitive status using a standard instrument known as the Minimum Data Set (MDS). We report a validation study to show that the MDS Cognitive Performance Scale (CPS), a cognitive measure generated from 5 MDS items (comatose status, decision making, short-term memory, making self understood, and eating) can be used to detect cognitive impairment as defined by the Mini-Mental State Examination (MMSE). METHODS: Two hundred subjects were randomly recruited from 8 nursing home facilities in North Carolina. Two medical students administered the MMSE, while a geriatric research nurse was responsible for collecting MDS cognitive items, which included the 5 items required for generating CPS scores. Cognitive impairment was defined by MMSE scores adjusted for education. Agreement between the CPS and the MMSE in identifying cognitively impaired subjects was then evaluated. RESULTS: The CPS showed substantial agreement with the MMSE in the identification of cognitive impairment; the sensitivity was .94 (95% confidence interval [CI]: .90, .98), the specificity was .94 (95% CI: .87, .96), and the diagnostic accuracy as measured by the area under the receiver operating characteristics (ROC) curve was .96 (95% CI: .88, 1.0). CONCLUSIONS: The MDS Cognitive Performance Scale, when performed by a trained research nurse using recommended protocols, provides a valid measure of cognitive status in nursing home residents.

Creating and validating practical measures for assessing public health practices in local communities.

Efforts to develop a surveillance system to measure local public health performance were initiated in 1991. The organizing framework for the proposed system consisted of three core functions formulated by the Institute of Medicine and linked with 10 practices previously defined. A surveillance protocol was developed using local public health jurisdictions rather than specific agencies within the jurisdictions, as the units of study. Selection of 84 indicators was assisted by follow-up study of a group of departments analyzed in 1979 and by review of recent public health literature. Each of the 84 performance indicators was linked to one of the 10 practices. Responses to the survey were obtained from local health department directors. Results yielded scores for the surveyed jurisdiction with regard to adequacy of performance for each practice, the proportional contribution to performance by the local health department, and the identification of other providers contributing to the coverage of each practice within the jurisdiction. A shortened version of the protocol (26 indicators) was tested in all local jurisdictions in six states and shown to correlate reliably with scores obtained from the longer protocol for overall public health performance, as well as for performance of each of the three core functions and for some of the 10 practices. A subset of four indicators was shown to predict reliably the overall score. The findings support the proposition that public health practice can be defined, measured, and monitored and that current widely accepted definitions of core functions and practices have utility. Measurement and surveillance tools for these functions and practices are available and tested.