Average Measures Intraclass Correlation Coefficient Research Articles

Objective Assessment of the Perineural Vascular Plexus as a Landmark for the Horizontal Part of the Facial Nerve in Middle Ear and Mastoid Surgery

To objectively evaluate the usefulness and the reliability of the perineural vascular plexus as a landmark for identification of the facial nerve in surgery for chronic squamous otitis media. Prospective case series. Tertiary otologic center. Seventy consecutive patients requiring surgery for cholesteatomatous otitis media. Use of a semiquantitative grading system intraoperatively to assess the utility and ease of using the perineural facial plexus as the pointer to the facial nerve. Description of the perineural vascular plexus and assessment of the reproducibility of the grading system. In 82.5% of patients, the plexus was used as the sole pointer to the level of the facial nerve, with other landmarks being used in the remaining 17.5%. A very prominent vessel was used to identify the nerve in 82.5%, therefore being classified as Grade 1. Multiple small vessels were seen in 15.8% (Grade 2), and in 1.5% the vessel plexus was thin and difficult to identify. The average measure intraclass correlation was 0.75 (95% confidence interval, 0.57-0.85), indicating excellent reproducibility of the system. We believe that the perineural vascular plexus is a dependable and reliable landmark for the level of the facial nerve in surgery for chronic otitis media.

Measurement of Resistance Exercise Force Expression

Displacement-based measurement systems are becoming increasingly popular for assessment of force expression variables during resistance exercise. Typically a linear position transducer (LPT) is attached to the barbell to measure displacement and a double differentiation technique is used to determine acceleration. Force is calculated as the product of mass and acceleration. Despite the apparent utility of these devices, validity data are scarce. To determine whether LPT can accurately estimate vertical ground reaction forces, two men and four women with moderate to extensive resistance training experience performed concentric-only (CJS) and rebound (RJS) jump squats, two sessions of each type in random order. CJS or RJS were performed with 30%, 50%, and 70% one-repetition maximum parallel back squat 5 minutes following a warm-up and again after a 10-min rest. Displacement was measured via LPT and acceleration was calculated using the finite-difference technique. Force was estimated from the weight of the lifter-barbell system and propulsion force from the lifter-barbell system. Vertical ground reaction force was directly measured with a single-component force platform. Two-way random average-measure intraclass correlations (ICC) were used to assess the reliability of obtained measures and compare the measurements obtained via each method. High reliability (ICC > 0.70) was found for all CJS variables across the load-spectrum. RJS variables also had high ICC except for time parameters for early force production. All variables were significantly (p < 0.01) related between LPT and force platform methods with no indication of systematic bias. The LPT appears to be a valid method of assessing force under these experimental conditions.

Reliability of a Structured Interview Scoring Instrument for a Canadian Postgraduate Emergency Medicine Training Program

To determine the reliability of scores assigned to interviews of medical students applying to an emergency medicine program. A scoring instrument was derived based on faculty and resident input, institutional and national documents, and previous application procedures. Candidates were interviewed by four pairs of interviewers. Interviewers were asked to score the candidates on five visual analog scales (VASs) with objective anchors. Each interview assessed a unique candidate characteristic. All interviewers were given explicit instructions on scoring procedures and instrument use. The data were entered into an Excel database and transferred to SPSS, and reliabilities were measured with a two-way mixed-effect Cronbach's alpha. Forty applications were received for the 2002 residency entry year. Thirty-eight application packages were complete, and 16 candidates were interviewed. Data collection was complete for all 16. The average measure intraclass correlations for each individual interviewer across the five VASs ranged from 0.72 to 0.92 (mean, 0.85). The interrater reliability within the four interviews (personal characteristics, trainability, suitability for emergency medicine, and suitability for the specific training program) were low at 0.36, 0.59, 0.69, and 0.49. The overall reliability of the four interview scores was 0.83, and for the eight interviewer scores it was 0.86. The reliability of the overall interview scores was very high. The intraclass correlations for each interviewer's VAS scores were also high, but interrater correlations within interview teams were moderate and not higher than those across interview teams. This study suggests that an interview assessment instrument can be highly reliable overall and that interviewers base scores on an overall global impression.

Reliability of digital videometry and acetate tracing in measuring the surface area of cutaneous wounds

Purpose: The purpose of this study was to evaluate the reliability of digital videometry and acetate tracing in the measurement of cutaneous wound area. Methods: Four clinicians used both digital videometry and acetate tracing to measure five wounds that were artificially created on a cadaver specimen. In addition, the clinicians used an analog centimeter ruler to determine a rough estimate of the area of each wound. The wounds were measured a total of five times with each measurement instrument using a non-sequential repeat measures design. Associations between the three wound measurement techniques were examined with Pearson correlation coefficients. In addition, intraclass correlation coefficients (ICC) were calculated for each pair of the three measurement techniques. Results: Correlation between the measurement systems for all raters combined yielded Pearson r-values of 0.93 for ruler and acetate, 0.95 for ruler and digital and 0.97 for acetate and digital. Furthermore, the average measure ICC between acetate and digital was 0.94, between acetate and ruler was 0.76 and between digital and ruler was 0.57. Conclusion: These results suggest that wound area measurements obtained using digital videometry and acetate tracing are very similar and both techniques can be used interchangeably in either clinical or research settings.