Tonsillectomy rates for Manitoba children: temporal and spatial variations.

This study compared tonsillectomy rates for Manitoba children across geographic regions and over time. Shortly after the publication of clinical guidelines for tonsillectomy, provincial rates of this procedure dropped by over 25% between 1994/95 and 1996/97. By 1998/99, rates for non-Winnipeg children had increased to pre-guideline levels, whereas the rates for Winnipeg children remained lower. Significant regional variation existed in all years examined, suggesting that quality of care remains an issue for this procedure.