title: Halo and spillover effect illustrations for selected beneficial medical devices and drugs.
abstract: Negative news media reports regarding potential health hazards of implanted medical devices and pharmaceuticals can lead to a 'negative halo effect,' a phenomenon whereby judgments about a product or product type can be unconsciously altered even though the scientific support is tenuous. To determine how a 'negative halo effect' may impact the rates of use and/or explantation of medical products, we analyzed the occurrence of such an effect on three implanted medical devices and one drug: 1) intrauterine contraceptive devices (IUDs); 2) silicone gel-filled breast implants (SGBI); 3) metal-on-metal hip implants (MoM); and 4) the drug Tysabri.
  
  
  
  Data on IUD use from 1965 to 2008 were gathered from the Department of Health and Human Services Vital and Health Statistics and peer-reviewed publications. Data regarding SGBI implant and explantation rates from 1989 to 2012 were obtained from the Institute of Medicine and the American Society of Plastic Surgeons. MoM implant and explantation data were extracted from the England and Wales National Joint Registry and peer-reviewed publications. Tysabri patient data were reported by Elan Corporation or Biogen Idec Inc. Data trends for all products were compared with historical recall or withdrawal events and discussed in the context of public perceptions following such events.
  
  
  
  We found that common factors altered public risk perceptions and patterns of continued use. First, a negative halo effect may be driven by continuing patient anxiety despite positive clinical outcomes. Second, negative reports about one product can spill over to affect the use of dissimilar products in the same category. Third, a negative halo effect on an entire category of medical devices can be sustained regardless of the scientific findings pertaining to safety. Fourth, recovery of a product's safety reputation and prevalent use may take decades in the U.S., even while these products may exhibit widespread use and good safety records in other countries.
  
  
  
  We conclude that the 'negative halo effect' associated with a stigma, rather than an objective risk-benefit assessment of medical products can increase negative health outcomes for patients due to reduced or inappropriate product usage.
authors.affiliation: Exponent, 320 Goddard, Suite 200, Irvine, CA, 92618, USA.
authors.forename: Brent D
authors.initials: BD
authors.lastname: Kerger
authors.affiliation: Cardno ChemRisk, 130 Vantis, Suite 170, Aliso Viejo, CA, 92656, USA. autumn.bernal@cardno.com.
authors.forename: Autumn
authors.initials: A
authors.lastname: Bernal
authors.affiliation: Cardno ChemRisk, 101 2nd St. Suite 700, San Francisco, CA, 94105, USA.
authors.forename: Dennis J
authors.initials: DJ
authors.lastname: Paustenbach
authors.affiliation: Huntley-Fenner Advisors, 5319 University Drive, #137, Irvine, CA, 92612, USA.
authors.forename: Gavin
authors.initials: G
authors.lastname: Huntley-Fenner
mesh_terms: D018427:Breast Implants / Q000523:psychology / Q000706:statistics & numerical data; D004739:England; D004869:Equipment Safety / Q000523:psychology*; D005260:Female; D006622:Hip Prosthesis / Q000523:psychology / Q000706:statistics & numerical data; D006801:Humans; D007155:Immunologic Factors / Q000627:therapeutic use; D007434:Intrauterine Devices / Q000706:statistics & numerical data; D008297:Male; D008402:Mass Media / Q000706:statistics & numerical data*; D061825:Metal-on-Metal Joint Prostheses / Q000523:psychology; D000069442:Natalizumab / Q000627:therapeutic use; D010342:Patient Acceptance of Health Care / Q000523:psychology* / Q000706:statistics & numerical data; D010820:Physicians; D019736:Prostheses and Implants / Q000523:psychology*; D020034:Silicone Gels; D014481:United States; D014852:Wales
chemical_list: D007155:Immunologic Factors; D000069442:Natalizumab; D020034:Silicone Gels
keywords: Intrauterine device; MoM hip implants; Product recall; Risk perception; Tysabri