Here is what I refer to in PROC HPLOGISTIC documentation. LACKFIT< (DFREDUCE=r NGROUPS=G) > performs the Hosmer and Lemeshow goodness-of-fit test (Hosmer and Lemeshow 2000) for binary response models. The subjects are divided into at most G groups of roughly the same size, based on the percentiles of the estimated probabilities. You can specify G as any integer greater than or equal to 5; by default, G=10. Let the actual number of groups created be g. The discrepancies between the observed and expected number of observations in these g groups are summarized by the Pearson chi-square statistic, which is then compared to a chi-square distribution with g–r degrees of freedom. You can specify a nonnegative integer r that satisfies g–r 1; by default, r=2. A small p-value suggests that the fitted model is not an adequate model. For more information, see the section “The Hosmer-Lemeshow Goodness-of-Fit Test” on page 4274. ... View more