The Population Burden of Chronic Symptoms that Substantially Predate the Diagnosis of a Life-Limiting Illness.

Many people in our communities live with symptoms for years or decades, something of relevance to hospice/palliative care clinicians and researchers. The proportion of people in the community at large who have a chronic symptom is likely to approximate the proportion of people referred to hospice/palliative care services with that same chronic symptom that pre-dates their life-limiting illness. Such patients may have different responsiveness to, and expectations from, symptomatic therapies, thus requiring more advanced approaches to symptom control. For researchers evaluating the impact of hospice/palliative care services, failing to account for people with long-term refractory symptoms pre-dating their life-limiting illness may systematically underestimate services' benefits. Observational symptom prevalence studies reported in hospice/palliative care to date have not accounted for people with long-term refractory symptoms, potentially systematically overestimating symptoms attributed to life-limiting illnesses. Cross-sectional community prevalence rates of key chronic refractory symptoms largely unrelated to their life-limiting illness reflect the likely prevalence on referral to hospice/palliative care: fatigue (up to 35%); pain (12%-31%); pain with neuropathic characteristics (9%); constipation (2%-29%); dyspnea (4%-9%); cognitive impairment (>10% of people >65 years old; >30% of people >85 years old); anxiety (4%); and depression (lifetime incidence 2%-15%; one year prevalence 3%). Prospective research is needed to establish (1) the prevalence and severity of chronic symptoms that pre-date the diagnosis of a life-limiting illness in people referred to hospice/palliative care services, comparing this to whole-of-population estimates; and (2) whether this group is disproportionately represented in people with refractory symptoms.