Possible missed opportunities for diagnosing colorectal cancer in Dutch primary care: a multimethods approach

Daan Brandenbarg, Feikje Groenhof, Ilse M Siewers, Anna van der Voort, Fiona M Walter, Annette J Berendsen

Early detection of colorectal cancer (CRC) is important to achieve better survival. Discriminating symptoms suggestive of CRC from benign conditions is a challenge for GPs because most known 'alarm symptoms' have low predictive values. To further understand the diagnostic process of CRC in general practice in terms of healthcare use and by analysing factors related to diagnostic intervals. A multimethod approach comprising a historical, prospective registry study and qualitative content analysis. Healthcare use in the year before referral for colonoscopy was compared between patients diagnosed with CRC and an age-, sex,- and GP-matched control population. Qualitative content analysis was performed on free texts in electronic patient records from a purposive sample of patients with CRC. Patients with CRC (n = 287) had 41% (25-59%) more face-to-face contacts and 21% (7-37%) more medication prescriptions than controls (n = 828). Forty-six per cent of patients with CRC had two or more contacts for digestive reasons, compared with 12.2% of controls, more often for symptoms than diagnoses. From qualitative analysis two themes emerged: 'possible missed diagnostic opportunities' and 'improvements in diagnostic process unlikely'. Possible missed diagnostic opportunities were related to patients waiting before presenting symptoms, doctors attributing symptoms to comorbid conditions or medication use, or doctors sticking to an initial diagnosis. Fewer missed diagnostic opportunities might occur if GPs are aware of pitfalls in diagnosing CRC: the assumption that symptoms are caused by comorbid conditions or medication, or relating complaints to pre-existing medical conditions. GPs also need to be aware that repeated digestive complaints warrant rethinking an earlier diagnosis.