Figure - PMC

Skip to main content

An official website of the United States government

Here's how you know

Here's how you know

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

View full-text article in PMC

. 2010 Dec 9;5(12):e14259. doi: 10.1371/journal.pone.0014259

Search in PMC
Search in PubMed
View in NLM Catalog
Add to search

This is an open-access article distributed under the terms of the Creative Commons Public Domain declaration which stipulates that, once placed in the public domain, this work may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose.

This is an open-access article distributed under the terms of the Creative Commons Public Domain declaration, which stipulates that, once placed in the public domain, this work may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose.

PMC Copyright notice

*p<0.05 tests the differences in mean values between cases and controls at each time point. † tests in controls only the differences in mean values at week 1–2 compared to baseline and at week 3–4 compared to baseline. These comparisons in cases were not significant. A mixed effect Tobit regression model was written which provided an estimate of the average effect of PcP+ compared to PcP− in each interval. A random effect subject effect was modeled to account for correlation between measurements on the same subject in the same interval. The value of the t-statistics, testing Ho: PcP parameter estimate = 0, was used to judge the statistical significance of the effect of PcP+, compared to PcP−.