NT-proBNP on Cobas h 232 in point-of-care testing: Performance in the primary health care versus in the hospital laboratory.

BACKGROUND: NT-proBNP may be useful for ruling out heart failure in primary health care. In this study we examined the analytical quality of NT-proBNP in primary health care on the Cobas h 232 point-of-care instrument compared with measurements performed in a hospital laboratory. MATERIALS AND METHODS: Blood samples requested for NT-proBNP were collected in primary health care (n = 95) and in a hospital laboratory (n = 107). NT-proBNP was measured on-site on Cobas h 232 instruments both in primary health care centres and at the hospital laboratory and all samples were also analyzed with a comparison method at the hospital. Precision, trueness, accuracy, and lot-variation were determined at different concentration levels and evaluated according to acceptance criteria. Furthermore user-friendliness was assessed by questionnaires. RESULTS: For Cobas h 232 repeatability CV was 8.5-10.7% in the hospital setting and 5.3-10.0% in the primary health care and within the analytical quality specifications, but higher than with the comparison method (< 4%). NT-proBNP results obtained in primary health care were significantly higher than by the hospital comparison method (bias ranged from 14.3-23.7%), whereas there was no significant bias when Cobas h 232 was used in the hospital setting (bias ranged from - 4.9 to 7.0%). User-friendliness of Cobas h 232 was overall acceptable. CONCLUSION: Cobas h 232 point-of-care instrument for measurement of NT-proBNP performed satisfactorily with regard to precision, user-friendliness, and lot-variation. A decrease in NT-proBNP levels observed in samples transported to a central laboratory needs further attention and investigation.

Clinical studies on posterior cruciate ligament tears have weak design.

Very few studies in the literature focus on isolated PCL injury. Recent studies are in general more optimistic with regard to the results than previous reports. There are few randomized controlled trials and few prospective comparative studies, which may limit the value of the reported results. The goal of the present study was to evaluate the methodology of published studies according to a well-established scoring system. Studies with a high success rate have a low score on methodology design. This study was based on systematic review and level 3 evidence. We performed a literature search and included studies in which the primary aim was to report the outcome after management of isolated PCL injury. The quality of the studies was evaluated using a modified Coleman methodology score, which results in a score between 0 and 100. Studies were also assessed with use of level-of-evidence rating. We collected data on the year of publication, reported results after surgery and conservative treatment, and the outcome scales used to assess the results. Forty studies were included. The average methodology score was 52. No significant difference in outcome was detected between conservative and surgical management. Our hypothesis that a low Coleman score would yield a good clinical result was not verified. This could be caused by the fact that there were very few studies with a high Coleman score. The Coleman methodology score correlated positively with the year of publication and with the level-of-evidence rating. In the 40 reported studies, 12 different outcome scales were used. In conclusion, the generally low methodological quality shows that caution is required when interpreting results after management of injury to the PCL. Firm recommendations on what treatment to choose cannot be given at this time on the basis of these studies. More attention should be paid to methodological quality when designing, conducting and reporting trials.