Exam 26: Evaluation of Methods

Random error is associated with ______, and systematic error is associated with ______.The degree of ______ is described by the standard deviation or the coefficient of variation.

Usually a method-evaluation study is performed to:

New analytical methods are usually developed to: 1)improve accuracy over existing methods. 2)allow automation. 3)increase labor in the laboratory. 4)reduce reagent costs.

Even when a method's performance is well documented by published evaluation studies, the new laboratory considering use of the method should evaluate ______ and perform ______ to verify acceptable performance in that laboratory.

It has been proposed that allowable error be either ______ or ______ of the reference range for an analyte, whichever is less.For enzymes, the limit is ______.

Which of the following factors can contribute to random analytical errors?

Interference should be evaluated for all commonly encountered interferents such as:

All of the following describe the within-run replication experiment except:

In judging analytical performance in the laboratory for a new method, it was found that the 95% upper limit of an error is smaller than the allowable error.It was also found that the 95% lower limit of error is greater than the allowable error.In this situation, what should the response of the technologist be?

The limit of detection: 1)is the minimum concentration of analyte whose presence can be qualitatively detected under defined conditions. 2)is the concentration at which an observed value will be very likely to exceed the limit of the blank. 3)is the highest value of a zero sample. 4)is the minimum concentration of analyte whose presence can be quantifiably measured reliably under defined conditions.

Which of the following statements is/are true regarding the correlation coefficient?

Calculate the percentage recovery given the following information: Baseline sample preparation: 1.5 mL serum + 0.25 mL water Spike sample preparation: 1.5 mL serum + 0.25 mL 5000 mg/L standard Baseline sample measured concentration: 950 mg/L Spiked sample measured concentration: 1621 mg/L

A method that falls in the six Sigma region of the Medical Decision Chart indicates that the relationship between the performance of the method and quality control is such that:

The within-run component of variation is caused by: 1)sampling and pipetting precision. 2)short-term variations in temperature of the instrument. 3)instability of the calibration curve. 4)short-term variations in the stability of the instrument.

Regression analysis of two methods produced the equation y = 0.137 + 0.813x.The proportionality between the two methods is:

Which of the following is the correct sequence to follow in method selection?

When considering application characteristics, emphasis may be placed on ______ for pediatric applications, on ______ for stat applications, and on ______ for high-volume screenings.