Kan en p-værdi være 1?

I studiet "Hydroxychloroquine with or without Azithromycin in Mild-to-Moderate Covid-19" (https://www.nejm.org/doi/full/10.1056/NEJMoa2019014#article_supplementary_material) konkluderer de følgende:

"As compared with standard care, the proportional odds of having a higher score on the seven-point ordinal scale at 15 days was not affected by either hydroxychloroquine alone (odds ratio, 1.21; 95% confidence interval [CI], 0.69 to 2.11; P=1.00) or hydroxychloroquine plus azithromycin (odds ratio, 0.99; 95% CI, 0.57 to 1.73; P=1.00)."

Altså leader det til, at man har fået en p-værdi på 1 (for begge medikamenter). Er dette overhoved muligt? Det virker meget mystisk