Volume 187 - Issue 4
Comparing survival outcomes for patients with colorectal cancer treated in public and private hospitals
Authors: Cameron Platell, Melinda Morris and Barry Iacopetta
Med J Aust 2007; 187 (4): 250-251. || doi: 10.5694/j.1326-5377.2007.tb01221.x
Published online: 20 August 2007
Published online: 20 August 2007
In reply: The first issue is whether we accurately identified patients with stage IV disease, as the incidence in our study was only 11% and the anticipated incidence is normally 20%–25%. We agree that simply reviewing pathology reports would tend to underdiagnose stage IV disease. However, all patients were crosschecked to the linked database to see if they had had a computed tomography scan or ultrasound image showing metastatic disease. In addition, we only reviewed patients whose primary cancer was resected. This excluded about a third of all the patients with stage IV disease. In my (C P) own surgical prospective colorectal cancer database of 781 patients, (1996 to 2007), 24% of the 185 referred with colorectal cancer had stage IV disease (private hospital patients, 21% v public hospital patients, 25%). Resection of the primary cancer was only undertaken in 126 of the 185 patients with stage IV disease (68%). Therefore, only 16% of all patients with colorectal cancer who had resections had stage IV disease (126/781).
Tebbutt argues that there could be a possibility of some imbalance between public and private patients based on this observation. We argue that the difficulty in diagnosing stage IV disease applies equally to public and private patients. Similarly, my own database does not show a significant difference in the incidence of stage IV disease between public and private hospital patients.
Kosmider et al report that, at their own institution, completion rates for chemotherapy for stage III colon cancers are the same for public and private patients, “. . . suggesting, in Victoria at least, similar access to care and support for public and private patients”. These results are hardly comparable with our study. Their observations are limited to a select subgroup and only relevant to a small section of the Victorian population, where there is a collocated public and private hospital. In contrast, our study included the entire population of Western Australia, and all public and private hospital patients. Interestingly, we noted wide variations in the rates at which chemotherapy was used, not only between public and private hospitals, but also between individual hospitals. We also noted that there are few collocated public and private hospitals within WA. The fact remains that, at a population level, public hospital patients in WA were less likely to receive chemotherapy.
Finally, Kosmider et al raise the issue that comorbidities can influence overall and cancer-specific survival (especially in relation to diabetes). We recognise this as a weakness of our study, and highlighted it in the discussion. Nonetheless, we did include a number of measures of social disadvantage in the analysis. Such measures can act as surrogate markers of common comorbidities. For example, there is a fairly clear association between type 2 diabetes and disadvantage.1 We therefore do not believe that comorbidities can account for all of the observations seen in our study. Our conclusion therefore remains — that patients with colon and rectal cancer treated in private hospitals in WA had superior outcomes. In reality, given the inequities between the two systems, is this really so surprising?
References
- Maty SC, Everson-Rose SA, Haan MN, et al. Education, income, occupation, and the 34-year incidence (1965–1999) of Type 2 diabetes in the Alameda County Study. Int J Epidemiol 2005; 34: 1274-1281. 0_BEABAABC