The NIH isn't the publisher of these studies. PubMed is effectively just a search engine for a wide range of documents. The NIH isn't affiliated with the studies PubMed hosts, so there are also occasionally studies on it of questionable repute. That being said, PubMed is still a great source of accurate studies and I have no opinion about this particular study. I just think the affiliation with the NIH needs to be clarified.

Edit: looking at the article's citation, it looks like this study was published by the Journal of the Brazilian Medical Association.