http://manuals.pqstat.pl/ 2026-04-04T04:18:05+00:00 http://manuals.pqstat.pl/ http://manuals.pqstat.pl/lib/tpl/dokuwiki/images/favicon.ico text/html 2022-02-16T09:53:57+00:00 Anonymous (anonymous@undisclosed.example.com) http://manuals.pqstat.pl/en:statpqpl:survpl:kmporpl:roznpl Differences among the survival curves Hypotheses: In calculations was used chi-square statistics form: where: - covariance matrix of dimensions where: diagonal: , off diagonal: -- number of moments in time with failure event (death), text/html 2022-02-16T09:56:11+00:00 Anonymous (anonymous@undisclosed.example.com) http://manuals.pqstat.pl/en:statpqpl:survpl:kmporpl:trendpl Survival curves trend Hypotheses: In the calculation the chi-square statistic was used, in the following form: where: -- vector of the weights for the compared groups, informing about their natural order (usually the subsequent natural numbers). text/html 2022-02-16T10:03:47+00:00 Anonymous (anonymous@undisclosed.example.com) http://manuals.pqstat.pl/en:statpqpl:survpl:kmporpl:warstwpl Survival curves for the stratas Often, when we want to compare the survival times of two or more groups, we should remember about other factors which may have an impact on the result of the comparison. An adjustment (correction) of the analysis by such factors can be useful. For example, when studying rest homes and comparing the length of the stay of people below and above 80 years of age, there was a significant difference in the results. We know, however, that sex has a strong influence on t…