The CDC's Morbidity and Mortality Weekly Report (MMWR) tends to have articles with many statistics (browse through various weeks).
Search for a condition/topic of interest in the large biomedical database PubMed. Try the following search strategy:
condition and statistics and "p value"
For example: stroke and statistics and "p value"
Note: in the above examples, the quote marks around p value tell the database to search the words next to each other, exactly as displayed between the quote marks