Prevalence of collusion in cancer communications: A meta-analysis.

Introduction: Collusion is the non-disclosure of information about diagnosis or prognosis, frequently encountered in cancer care and palliative services. Unraveling collusion is a skill and differences among communication techniques by Health Care Workers have maintained the process of non-disclosure to patients and caregivers. Identifying the prevalence of collusion in cancer care is required to improve the existing strategies across the world.

Methods: A systematic review of the literature from 1991 to 2020 in the English language was conducted with the protocol registration on PROSPERO ID (CRD 42021249216.) to identify the pooled prevalence of collusion.

Results: By using random effect model, the pooled prevalence estimate among patients for the diagnostic and prognostic collusion was 24.15, (95% CI [17.09; 32.96], Tou2 = 1.0801, I²  = 97.9%, Cochran's Q = 1058.22, df = 21, p-value < 0.001) and 37.92, (95% CI [22.46; 56.30], Tou2 = 1.9641, I²  = 98.6%, Cochran's Q = 944.26, df = 13, p-value < 0.001) respectively. There was no difference across subgroups with different types of setting for the interview, WHO regions and trend over the years.

Conclusions: Substantial prevalence of collusion goes unnoticed in cancer care. A meaningful understanding of such a large prevalence requires inquiry into the existing communication paradigm in cancer care across the world. The findings also question the need of formulating uniform interview techniques and structured assessment tools or questionnaires in cancer care to improve the disclosure rates.