> An important contribution to long-term sickness volumes has come from the large number of "baby boomers" (those born between 1946 and 1964) approaching retirement.

Anecdata from my parents peer group (born early 60s, working class) indicate that at least some of these people are faking it for a soft landing into retirement.

They had a taste of retirement with furlough and they simply don't want to work any more. They don't need to, either, because asset inflation (including property inflation in suburban London) has subsidised their lifestyle for years and will continue to subsidise their retirement.