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Biomedical subjects

J Pottinger

Publications and source records attributed to J Pottinger.

4 recordsLinked to original sources

The numbers game: sample-size determination.

Sample-size determination is a crucial component of study design. Estimates of sample size are influenced by the amount of change that must occur between study groups and the degree of risk that the investigator is willing to accept in evaluating the null hypothesis. A complete understanding of the impact of sample size on the interpretation of study data is therefore a prerequisite for quality, innovative, valid research.

Epidemiologic Factors↗

Effect of instructions on isokinetic trunk strength testing variability, reliability, absolute value, and predictive validity.

Although isokinetic strength testing has been in use for more than two decades, and numerous studies have addressed isokinetic performance of the lumbar spine, the effect of instructions on isokinetic trunk strength has not been studied. In a sample of 30 healthy women, this study examined the effect of "high-demand" instructions on lumbar strength performance. High-demand instructions were found to have a substantial positive effect on performance variability, reliability, absolute magnitude, and validity. Under these conditions, isokinetic trunk strength was found to be predictive of performance in a frequent lifting-lowering task.

Adult↗

Bacterial carriage by artificial versus natural nails.

Although health care workers are following fashion trends when they wear artificial nails, the implications of these nails for infection control is unknown. Cultures were obtained before and after handwashing from the fingertips of 56 nurses with artificial nails and 56 nurses with natural nails. After handwashing there were higher numbers of colony-forming units of gram-negative rods cultured from the fingertips of nurses with artificial nails than from nurses with natural nails. There were no significant differences in carriage of gram-positive cocci or normal flora. Because of the number of nosocomial infections caused by gram-negative rods, health care workers who wear artificial nails should consider the potential risk of increased carriage of gram-negative rods.

Adult↗