Can a complex community and GP intervention reduce time to cancer diagnosis in rural Western Australia?

Problem

While overall survival for most common cancers in Australia is improving, the rural-urban differential has been widening, with significant excess deaths due to lung, colorectal, breast and prostate cancer in rural Australia. Internationally a major focus on understanding variations in cancer outcomes has been later presentation to healthcare and later diagnosis. Approaches to reducing time to diagnosis of symptomatic cancer include public symptom awareness campaigns and interventions in primary care to improve early cancer detection, including the use of symptom risk assessment tools.

Approach

Design: 2x2 factorial cluster randomised controlled trial. Community Intervention: symptom awareness campaign tailored for rural Australians delivered through a community engagement model. GP intervention: resource card with symptom risk assessment charts and local referral pathways implemented through multiple academic detailing visits. Participants were eligible if diagnosed with breast, colorectal, lung or prostate cancer and resided in rural Western Australia. Primary outcome: Total Diagnostic Interval, defined as duration from first symptom (or date of cancer screening test) to cancer diagnosis. Interventions were delivered over two years and participants recruited during the intervention period and for a further three months.

Findings

1,358 eligible participants were recruited, representing 52% of all eligible cancer patients in the trial regions diagnosed during the accrual period. There were no significant differences in the Total Diagnostic Interval (TDI) at a Campaign or GP intervention level (Median TDI: Campaign Intervention 107.5 days; Campaign Control 92 days; GP Intervention 97 days; GP Control 96.5 days). Similarly, there were no significant differences in the TDI by factorial design, when analysed by tumour group or by sub-intervals of the TDI.

Consequences

This is the first large-scale cluster randomised trial to test the combined effects of community and GP level interventions on time to cancer diagnosis. We found no effect of either the community campaign or GP interventions. This may reflect limited dose of the interventions, especially of the community campaign where we could not use television because of the risk of contamination. The limited duration of follow-up after completion of the interventions may have missed effects which take time to accumulate or our selection of primary outcome may simply have been too ambitious for these types of intervention. Alternatively, these interventions do not have a measurable effect on time to cancer diagnosis.