nonconcurrent

Currently, there is debate as to whether nonconcurrent studies represent a real threat from history effects.

Nonconcurrent multiple baseline studies apply treatment to several individuals at delayed intervals.

For this reason, perhaps, nonconcurrent multiple baseline experiments are recommended for research in an educational setting.

Another issue complicating comparisons of outcomes among nonconcurrent series of patients is the possibility of changes in criteria for histologic diagnosis of prostate cancer.

Pfister DG, Wells CK, Chan CK, et al.: Classifying clinical severity to help solve problems of stage migration in nonconcurrent comparisons of lung cancer therapy.

An analysis of data using historical controls from the National Polyp Study (NPS) has commonly been cited to show a reduction of 76% to 90% in the subsequent incidence of CRC after colonoscopic polypectomy compared with three nonconcurrent, historical control groups.

James Berg, president of the Realty Advisory Board on Labor Relations, which represents those 3,000 buildings, including rentals, in Brooklyn, Queens, Manhattan and Staten Island (the Bronx has a separate, nonconcurrent contract), said: "We're pretty certain there will be proposals for substantial increases in wages and benefit costs.