Notice: On April 23, 2014, Statalist moved from an email list to a forum, based at statalist.org.

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

From |
"Matthew Baldwin, MD" <mrb45@columbia.edu> |

To |
statalist@hsphsun2.harvard.edu |

Subject |
st: Hosmer Lemeshow table incorrectly reported probabilities? |

Date |
Thu, 25 Aug 2011 17:40:42 -0400 |

Dear Statlisters,

Logistic model for death2, goodness-of-fit test (Table collapsed on quantiles of estimated probabilities) +--------------------------------------------------------+ | Group | Prob | Obs_1 | Exp_1 | Obs_0 | Exp_0 | Total | |-------+--------+-------+-------+-------+-------+-------| | 1 | 0.0958 | 15 | 20.1 | 296 | 290.9 | 311 | | 2 | 0.1757 | 47 | 41.7 | 264 | 269.3 | 311 | | 3 | 0.3006 | 66 | 73.3 | 245 | 237.7 | 311 | | 4 | 0.4494 | 119 | 114.8 | 192 | 196.2 | 311 | | 5 | 0.9328 | 183 | 180.2 | 127 | 129.8 | 310 | +--------------------------------------------------------+ number of observations = 1554 number of groups = 5 Hosmer-Lemeshow chi2(3) = 3.46 Prob > chi2 = 0.3265 Here are my calculations for expected probabilities based on the table: x (expected mortality) y (observed mortality) 20.1/311 = 0.065 15/311 = 0.048 41.7/311 = 0.13 47/311 = 0.15 73.3/311 = 0.24 66/311 = 0.21 114.8/311 = 0.37 119/311 = 0.38 180.2/310 = 0.58 183/310 = 0.58 Can anyone explain how the expected probabilities in the table were derived?

Thanks, Matthew Baldwin, MD Department of Pulmonary, Allergy, and Critical Care Medicine New York Presbyterian Hospital Columbia University College of Physicians and Surgeons * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/

**Follow-Ups**:**st: RE: Hosmer Lemeshow table incorrectly reported probabilities?***From:*"Visintainer, Paul" <Paul.Visintainer@baystatehealth.org>

**Re: st: Hosmer Lemeshow table incorrectly reported probabilities?***From:*Steven Samuels <sjsamuels@gmail.com>

- Prev by Date:
**st: placing two textboxes in a graph on the x-axis** - Next by Date:
**st: dfuller: Why is Stata using the t-distribution when I use "drift"** - Previous by thread:
**st: placing two textboxes in a graph on the x-axis** - Next by thread:
**Re: st: Hosmer Lemeshow table incorrectly reported probabilities?** - Index(es):