suggest substantial variability, often with over 25% of rates being in upper
For persons in discrete core studies, 55 different studies
provided 170 rates. The median value for rates was 15.2 per 100,000. The
distribution was positively skewed. Excluding the top and lower 10% of the
distribution, rates ranged from 7.7 to 43.0 per 100,000 (a five-fold
difference). Because schizophrenia has a relatively low incidence rate, zero
provides an absolute 'floor' for the rate distribution. NB while the lower
tails of the distributions were usually data-sparse, many of the
distributions had upper tails that contained more than 25% of the rates.
Several of the distributions had marked positive skewness. Thus deviation is
predominantly for high rates, rather than low rates.