title: The impact of having both cancer and diabetes on patient-reported outcomes: a systematic review and directions for future research.
abstract: OBJECTIVE
  This systematic review aims to summarize the current literature regarding potential effects of having both cancer and diabetes on patient-reported outcomes (PROs) and to provide directions for future research.
  
  
  METHODS
  MEDLINE, The Cochrane Library, CINAHL, and PsycINFO were searched from inception to January 2015. All English peer-reviewed studies that included patients with both cancer and diabetes and assessed PROs were included. All included studies were independently assessed on methodological quality by two investigators.
  
  
  RESULTS
  Of the 3553 identified studies, 10 studies were included and all were considered of high (40%) or adequate (60%) methodological quality. Eight of the 10 studies focused on health-related quality of life (HRQoL), functioning, or symptoms and 2 studies assessed diabetes self-management. Overall, HRQoL and functioning was lower, and symptoms were higher among patients with both cancer and diabetes as compared to having cancer or diabetes alone. Furthermore, one study reported that diabetes self-management was impaired after chemotherapy.
  
  
  CONCLUSIONS
  Having both cancer and diabetes resulted in worse PROs compared to having either one of the diseases, however, the considerable heterogeneity of the included studies hampered strong conclusions. Future studies are needed as this research area is largely neglected. As the majority of the included studies focused on HRQoL, future research should address the impact of both diseases on other PROs such as depression, patient empowerment and self-management.
  Having both cancer and diabetes might result in worse PROs, however, more research is needed as current evidence is scarce.
authors.affiliation: CoRPS-Center of Research on Psychology in Somatic diseases, Department of Medical and Clinical Psychology, Tilburg University, P.O. Box 90153, 5000 LE, Tilburg, The Netherlands. p.a.j.vissers@tilburguniversity.edu.|Department of Research, Netherlands Comprehensive Cancer Organisation, Eindhoven, The Netherlands. p.a.j.vissers@tilburguniversity.edu.
authors.forename: Pauline A J
authors.initials: PA
authors.lastname: Vissers
authors.affiliation: Center for Behavioral Cardiovascular Health, Columbia University Medical Center, New York, NY, USA.
authors.forename: Louise
authors.initials: L
authors.lastname: Falzon
authors.affiliation: CoRPS-Center of Research on Psychology in Somatic diseases, Department of Medical and Clinical Psychology, Tilburg University, P.O. Box 90153, 5000 LE, Tilburg, The Netherlands.|Department of Research, Netherlands Comprehensive Cancer Organisation, Eindhoven, The Netherlands.
authors.forename: Lonneke V
authors.initials: LV
authors.lastname: van de Poll-Franse
authors.affiliation: CoRPS-Center of Research on Psychology in Somatic diseases, Department of Medical and Clinical Psychology, Tilburg University, P.O. Box 90153, 5000 LE, Tilburg, The Netherlands.
authors.forename: Frans
authors.initials: F
authors.lastname: Pouwer
authors.affiliation: CoRPS-Center of Research on Psychology in Somatic diseases, Department of Medical and Clinical Psychology, Tilburg University, P.O. Box 90153, 5000 LE, Tilburg, The Netherlands.|Department of Research, Netherlands Comprehensive Cancer Organisation, Eindhoven, The Netherlands.
authors.forename: Melissa S Y
authors.initials: MS
authors.lastname: Thong
mesh_terms: D003920:Diabetes Mellitus / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008297:Male; D009369:Neoplasms / Q000175:diagnosis*; D063868:Patient Outcome Assessment; D011788:Quality of Life / Q000523:psychology*; D017741:Survivors / Q000523:psychology*
keywords: Cancer; Diabetes; Health-related quality of life; Patient-reported outcomes; Systematic review