This report analyses complaints made to the Health and Disability Commissioner. It investigate issues concerning delayed diagnosis of cancer by general practitioners (GPs) in New Zealand. During 1990-2015, 243 GPs were complained about in relation to this issue, with the number per year increasing significantly over that time. While this is consistent with general complaint trends, complaints about delayed cancer diagnosis in 2015 comprise a significantly larger percentage of all complaints about GPs than was the case a decade ago.
Colorectal and lung cancers were the cancers most commonly involved in the complaints to HDC about delayed cancer diagnosis, and the diagnostic delays were often lengthy. Complaints about the delayed diagnosis of breast cancer were found to be less common and involved shorter delays.
The factors found to typically contribute to the delayed diagnosis of cancer by GPs can be grouped into four main categories, depending on the stage at which they occur in the diagnostic process: consultation factors, diagnostic factors, follow-up and referral, and patient factors. Within these main categories are a number of subcategories of delayed diagnosis factors which may be at issue in any particular case. In the HDC complaints, the most commonly seen delayed diagnosis factors related to: the cancer presenting with non-specific or atypical symptoms, poor communication with secondary care, appropriate referrals not being made, inappropriate reliance on negative test results, and the GP failing to adequately take, review or consider relevant patient history.
The delayed diagnosis factors that were present in the complaints varied by type of cancer involved. However, for colorectal, lung, skin and breast cancers, the most common issue was the non-specific or atypical presentation of symptoms. Delayed colorectal cancer diagnosis was significantly associated with the failure to conduct an appropriate examination, and the treating of symptoms in isolation, compared to other cancer types. Issues of co-morbidities drawing focus, and inappropriate reliance on test results were characteristic of complaints relating to a delayed diagnosis of lung cancer. Delayed diagnosis of skin cancer was significantly associated with the patient not reporting their symptoms, and delay in prostate cancer diagnosis was strongly associated with the failure to follow-up test results.
There are various learnings that arise from the cases that may assist in decreasing diagnostic error among GPs. Some of these are things for GPs to focus on, while others may assist with patient engagement in the diagnostic process.
For GPs, the cases, and the trends and themes that emerge from them, suggest that additional
focus could be given to:
- undertaking clinically indicated examinations and tests;
- examining patients in the context of their past history;
- ensuring comprehensive documentation is kept;
- being aware of limitations of diagnostic testing (e.g. false negative rates);
- considering all clinically relevant differential diagnoses;
- continuing to hold a suspicion for cancer despite co-morbidities;
- not treating symptoms in isolation;
- providing safety-netting advice to patients;
- having robust follow-up systems; and
- advocating for patients in the secondary care system.
For patients, diagnostic error, including length of any diagnostic delay may be lessened by
- attendance at follow-up appointments;
- reporting all symptoms to the GP; and
- proactively following up on test results and referrals.