Imprecision of high-sensitivity cardiac troponin assays at the female 99th-percentile.

BACKGROUND: An analytical benchmark for high-sensitivity cardiac troponin (hs-cTn) assays is to achieve a coefficient of variation (CV) of ≤ 10.0 % at the 99th percentile upper reference limit (URL) used for the diagnosis of myocardial infarction. Few prospective multicenter studies have evaluated assay imprecision and none have determined precision at the female URL which is lower than the male URL for all cardiac troponin assays. METHODS: Human serum and plasma matrix samples were constructed to yield hs-cTn concentrations near the female URLs for the Abbott, Beckman, Roche, and Siemens hs-cTn assays. These materials were sent (on dry ice) to 35 Canadian hospital laboratories (n = 64 instruments evaluated) participating in a larger clinical trial, with instructions for storage, handling, and monthly testing over one year. The mean concentration, standard deviation, and CV for each instrument type and an overall pooled CV for each manufacturer were calculated. RESULTS: The CVs for all individual instruments and overall were ≤ 10.0 % for two manufacturers (Abbott CVpooled = 6.3 % and Beckman CVpooled = 7.0 %). One of four Siemens Atellica instruments yielded a CV > 10.0 % (CVpooled = 7.7 %), whereas 15 of 41 Roche instruments yielded CVs > 10.0 % at the female URL of 9 ng/L used worldwide (6 cobas e411, 1 cobas e601, 4 cobas e602, and 4 cobas e801) (CVpooled = 11.7 %). Four Roche instruments also yielded CVs > 10.0 % near the female URL of 14 ng/L used in the United States (CVpooled = 8.5 %). CONCLUSIONS: The number of instruments achieving a CV ≤ 10.0 % at the female 99th-percentile URL varies by manufacturer and by instrument. Monitoring assay precision at the female URL is necessary for some assays to ensure optimal use of this threshold in clinical practice.

The significance and impact of a faculty teaching award: disparate perceptions of department chairs and award recipients.

Teaching awards are commonly regarded as an incentive to encourage pedagogic excellence. Inasmuch as their effectiveness depends on how they are perceived by faculty, the authors investigated the impact of a teaching award in the Faculty of Medicine (Faculty Honor List for Educational Excellence) on the attitudes of award recipients and departmental chairs. A questionnaire was designed to sample opinion on the extent to which the Honor List program was publicized, whether the award contributed to recognition and/or stature in the academic unit, and whether it was personally valued by recipients. The questionnaire was sent to all 23 departmental chairs and to all 43 faculty members who had received the award between 1998 and 2002; 78% of the chairs and 77% of the recipients responded. The results revealed marked discrepancies between the perceptions of chairs and recipients. Chairs, although uncertain of the effect on quality of teaching, largely regarded the award as prestigious and well publicized within their departments. A notably smaller percentage of award recipients shared these views. Nonetheless, 93% of recipients valued the award highly, and 45% of recipients indicated that the award inspired them to enhance the quality of their teaching.