Precision and accuracy of point‐of‐care testing coagulometers used for self‐testing and self‐management of oral anticoagulation therapy

Summary. Background: Oral anticoagulation therapy is monitored by the use of the International Normalized Ratio (INR). Patients who perform self‐testing or self‐management use a point‐of‐care testing (POCT) coagulometer (INR monitor) to estimate their INRs. A precondition for a correct dosage of coumarins is a correct INR estimation, and the method and apparatus used for providing the INR measurements are crucial in this context. Several studies have been published regarding the precision and accuracy of these POCT coagulometers, and have led to diverse conclusions. It is difficult and challenging to perform an overview of the literature, owing to the vast amount of papers, with differences in design, statistical analysis, etc. Objectives: The aim of this systematic review was to analyze the current literature, especially regarding the precision and accuracy of the POCT coagulometers, to provide recommendations for clinical use and quality control, and to point out areas for future research. Methods: We included a total of 22 studies, of which four were characterized as high‐quality studies. Results: The precision of the POCT coagulometers was generally adequate for clinical use. Their performance in terms of accuracy has to be viewed in the context of the inherent inaccuracies of INR measurements. Conclusions: The accuracy of POCT coagulometers seems, in this respect, to be generally acceptable, and they can be used in a clinical setting.     

Cluster randomized controlled trial testing the effectiveness of a self‐management intervention using the teach‐back method for people with heart failure

In this study, we examined the effectiveness of a self‐management intervention delivered to people with heart failure in Vietnam. It used teach‐back, a cyclical method of teaching content, checking comprehension, and re‐teaching to improve understanding. A single‐site cluster randomized controlled trial was conducted, and six hospital wards were randomized into two study groups. On the basis of ward allocation, 140 participants received either usual care or the teach‐back heart failure self‐management intervention plus usual care. The intervention involved, prior to discharge, an individual educational session on heart failure self‐care, with understanding reinforced using teach‐back, a heart failure booklet, weighing scales, diary, and a follow‐up phone call 2 weeks post‐discharge. The control group received usual care and the booklet. Outcomes were heart failure knowledge, self‐care (maintenance, management and confidence), and all‐cause hospitalizations assessed at 1 and 3 months (end‐point). Upon completion of the study, the intervention group had significantly greater knowledge and self‐care maintenance than the control group. Other outcomes did not differ between the two groups. The teach‐back self‐management intervention demonstrated promising benefits in promoting self‐care for heart failure patients.     

Confidence‐weighted testing: A descriptive study of Japanese nursing students

Nurses' lack of self‐confidence in their own nursing skills is one of the main reasons that novice nurses leave the profession in Japan. Nursing education must help students gain self‐confidence in their nursing skills in order to allow more novice nurses to stay in their profession. In this study, we evaluated whether confidence‐weighted testing feedback actually improves students' self‐confidence in their basic nursing skills. Confidence‐weighted testing, which provides quantifiable results, might allow students to objectively assess their skill‐related self‐confidence. Sixty‐seven first‐year nursing students took two confidence‐rating examinations on the knowledge and practical skills related to pulse and blood pressure measurement of immobile patients. Feedback was given to each participant after the first examination. After the first examination with confidence‐weighted testing feedback, students showed higher levels of self‐confidence in their practical skills, but not in knowledge. The improvement of self‐confidence in practical skills suggests that there is still room for improvement in confidence‐weighted testing feedback in knowledge. Further research is required to identify more effective feedback methods to improve students' self‐confidence levels in knowledge using the results of confidence‐weighted testing.     

A new method to quantify postexercise ST‐deviation – the ST‐deficit. A study in men at high and low‐risk for coronary heart disease

Background Quantitative heart rate adjusted exercise ST criteria like μV/beats per minute (bpm) improve the diagnostic accuracy of the exercise ECG. However, there are few quantitative HR adjusted postexercise variables available. The aim of the present exercise study was to evaluate a new such variable from computerized averaging of the postexercise ECG. Methods The presence of possible myocardial ischaemia in a population based sample of 74 elderly male hypertensives at high‐risk of coronary heart disease, and in 42 age‐matched clinically healthy males (reference group) at low‐risk was assessed by exercise ECG. All men had a normal resting ECG without signs of ischaemia. Variables studied: standard ST‐criteria, ST/HR slope ≤–2·4 μV · bpm^–1, shape of the rate‐recovery loop, the latter also with a new quantitative variable, the ST‐deficit. Results In spite of a normal resting ECG many subjects showed an abnormal ST/HR slope during exercise, 43% in the hypertension group and 26% in the reference group. An abnormal rate‐recovery loop (ST‐deficit) also contributed substantially to identify patients with possible myocardial ischaemia, 30 vs. 10%, respectively (P<0·02); cumulatively for the two HR adjusted criteria 53% vs. 29%, respectively (P<0·02). Mean ST‐deficit was significantly lower in the high‐risk group. Conclusions Effort‐related myocardial ischaemia is frequently silent in elderly high‐risk hypertensives and necessitates testing, preferably with computerized exercise ECG and heart rate adjusted ST criteria. A new quantitative variable to assess the postexercise rate‐recovery loop in the time domain, the ST‐deficit is described. This variable seems to effectively discriminate between subjects with low and high‐risk for coronary heart disease and thus provides new information. Further studies are warranted to validate this variable against myocardial perfusion scintigraphy and coronary angiography.