"Patients with suspected cancer in parts of England are 60 times more likely to be sent for scans than those living elsewhere."
Daily Mail, 9 August 2012
After David Cameron's awkward radio encounter with a cancer patient unable to get treatment under the NHS, the Daily Mail reported on how quality of NHS cancer care can widely differ according to a something as seemingly superfluous as a patient's postcode.
Referencing research by the National Cancer Intelligence Network (NCIN), the Mail claimed the disparity is so large that a suspected cancer patient in one part of England could be 60 times more likely to be sent for an urgent scan than patients in another area.
But is this true?
The NCIN data the Mail refers to is the General Practice Profiles for Cancer, published in July 2011. The profiles are the first published statistics on cancer referrals made by individual GP practices.
The Profiles provide data on referrals made by 7,984 GP practices between 2010 and 2011, providing averages for each Primary Care Trust (PCT).
Data was collected from Quality and Outcomes Framework (QOF), the NHS data system collating information on the performance and payment of GP practices.
Among other things, the General Practice Profiles measure the rate of GP referral of a patient to have an urgent cancer scan in each practice between 2010 and 2011.
Looking at the two extreme GP practices, the practice with the lowest referral rate in 2011 was in Hillingdon PCT in West London, which had a rate of 89 per 100,000 patients a year. Whereas the practice with the highest rate was in Sefton PCT, near Liverpool, which had a recorded referral rate of 5,637 per 100,000.
This means that a patient in the practice in Hillingdon PCT is indeed approximately 60 times less likely than a patient in the Sefton PCT practice to be referred for a cancer scan.
But does this correct calculation mean that Daily Mail has represented the NCIN data fairly? Not necessarily.
As a reminder, the Mail's claim was that suspected cancer patients living in one area have a greater likelihood of being referred for a scan than suspected cancer patients in other areas.
However, the NCIN data to which the Mail refers does not measure the rate at which suspected cancer patients referred for scans, but the rate at which patients in the practice became suspected cancer cases and were put through the two-week wait referral system for a cancer scan.
For example, taking the Hillingdon PCT practice, 89 per 100,000 patients a year were identified by GPs as potentially having cancer and referred for a scan. However, this is not what the Daily Mail reports, interpreting the data as only 89 out of 100,000 suspected cancer patients a year were referred for a scan.
This is an important difference in terms. The NCIN data does not imply that when a GP in the Hillingdon practice suspects a patient may have cancer, they are less likely to send them for a scan than a GP in the Sefton practice. The difference between the two practices reflects a disparity in the number of patients being diagnosed as a suspected cancer case, rather than a difference in GP reaction to a cancer case.
A problem for quality of care?
It's also worth pointing out that the sixty-fold difference represents the difference between two extreme cases. The general range between GP referral rates across England is less extreme (though not insignificant), with the majority of rates falling between 830 per 100,000 a year and 2,550 per 100,000.
The last caveat concerns how far we can interpret these NCIN figures as an indication of a differing quality in cancer care across areas in England. The range of referral rates may be affected by other factors than simply quality of care.
The study acknowledged that the size of the population served by each practice, as well as the proportion of patients over 65 years of age could affect different referral rates and took account of them accordingly.
"The data are not easy to interpret, since we do not know what the optimum level is for these measures. Although the data are adjusted for age, there may be other differences in the characteristics of the patients of a particular GP practice that impact on local referral rates. However, the range of the variation is so wide that, at the extremes, it probably reflects differing standards of care."
So, due to lack of conclusive understanding, we can't use the data as a crystal clear reflection of differing qualities in cancer care across England. What the statistics do perhaps indicate is a differing standard in care between the extremes. So, it is, according to the NCIN data, likely that the cancer care at the GP practice in Hillingsdon is of a lesser quality than that in the Sefton practice.
Although featuring a correct calculation from the NCIN data, the Daily Mail does not accurately report the statistics.
While the newspaper suggests that patients with suspected cancer are 60 times more likely to be referred for scans in some parts of the country compared to others, the figures actually show the rate at which patients in the practice became suspected cancer cases, and put onto a waiting list for referral.
The data cannot however be used as a conclusive indication of which GP practices have a higher or lower quality of care. However, according to the NCIN's Clinical Lead, such a wide disparity in the ranges does at least indicate a differing standard in care between the extremes.