The overall ratings of 4 Health Care Providers & Services stocks are down on Portfolio Grader this week. Each of these rates a “D” (“sell”) or “F” overall (“strong sell”).

Patterson Companies, Inc. (PDCO) gets weaker ratings this week as last week’s C drops to a D. Patterson Companies, Inc. distributes dental products, veterinary supplies for companion pets, and rehabilitation supplies. For more information, get Portfolio Grader’s complete analysis of PDCO stock.

Community Health Systems, Inc.’s (CYH) rating weakens this week, dropping to a F versus last week’s D. Community Health Systems, Inc. provides healthcare services through hospitals that it owns and operates in the United States. The company also gets F’s in earnings revisions, earnings surprise, and earnings momentum. For more information, get Portfolio Grader’s complete analysis of CYH stock.

Select Medical Holdings Corporation (SEM) slips from a C to a D this week. Select Medical Holdings Corporation is an operator of specialty hospitals and outpatient rehabilitation clinics. For more information, get Portfolio Grader’s complete analysis of SEM stock.

Universal American Corp. (UAM) declines this week from a C to a D. Universal American Corp. is a life and accident and health insurance holding company. The company also gets F’s in earnings revisions, earnings surprise, and earnings momentum. For more information, get Portfolio Grader’s complete analysis of UAM stock.

Louis Navellier’s proprietary Portfolio Grader stock ranking system assesses roughly 5,000 companies every week based on a number of fundamental and quantitative measures. Stocks are given a letter grade based on their results — with A being “strong buy,” and F being “strong sell.” Explore the tool here.