This week, 3 Health Care Equipment & Supplies stocks are worse, according to the Portfolio Graderdatabase. Each of these rates a “D” (“sell”) or “F” overall (“strong sell”).

Quidel Corporation’s (QDEL) rating weakens this week, dropping to a F versus last week’s D. Quidel Corporation discovers, develops, manufactures, and markets rapid diagnostic products for point-of-care detection of human medical conditions and illnesses. The company also gets F’s in earnings revisions and earnings surprise. For more information, get Portfolio Grader’s complete analysis of QDEL stock.

This week, Dehaier Medical Systems Ltd.’s (DHRM) rating worsens to a D from the company’s C rating a week ago. Dehaier Medical Systems Ltd. engages in the development and distribution of medical devices and related products in the People’’s Republic of China. The company also gets F’s in sales growth, operating margin growth, earnings growth, return on equity, and free cash flow. For more information, get Portfolio Grader’s complete analysis of DHRM stock.

Capnia Inc (CAPN) earns a D this week, moving down from last week’s grade of B. The company also gets F’s in free cash flow. For more information, get Portfolio Grader’s complete analysis of CAPN 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.