Statistical analyses in German radiological periodicals: The last decade'sdevelopment.

Purpose: To identify which statistical tests are applied in German radiolog ical publications, to what extent their use has changed during the last dec ade, and which factors might be responsible for this development. Materials and Methods: The major articles published in "ROFO" and "DER RADIOLOGE" du ring 1988, 1993 and 1998 were reviewed for statistical content. The contrib utions were classified by principal focus and radiological subspecialty. Th e methods used were assigned to descriptive, basal and advanced statistics. Sample size, significance level and power were established. The use of exp erts' assistance was monitored. Finally, we calculated the so-called cumula tive accessibility of the publications. Results: 525 contributions were fou nd to be eligible. In 1988, 87% used descriptive statistics only, 12.5% bas al, and 0.5% advanced statistics. The corresponding figures in 1993 and 199 8 are 62 and 49%, 32 and 41%, and 6 and 10%, respectively. Statistical tech niques were most likely to be used in research on musculoskeletal imaging a nd articles dedicated to MRI. Six basic categories of statistical methods a ccount for the complete statistical analysis appearing in 90% of the articl es. ROC analysis is the single most common advanced technique. Authors make increasingly use of statistical experts' opinion and programs. Conclusions : During the last decade, the use of statistical methods in German radiolog ical journals has fundamentally improved, both quantitatively and qualitati vely. Presently, advanced techniques account for 20% of the pertinent stati stical tests. This development seems to be promoted by the increasing avail ability of statistical analysis software.