"chronically sick" is correct and usable in written English.
You could use it to describe someone with an illness or condition that has gone on for a long period of time. For example, "She has been chronically sick since she was a young child."
The diseases held responsible for chronic sickness were awse (trypanosomiasis; 55% of all chronically sick animals in 21 herds), mbooru/njoobu (foot-and-mouth disease; 17%), sondaru (cough; 17%), and baakaale (brucellosis; 11%).
Pastoralists in the far north region of Cameroon, for example, do not always remove chronically sick animals from their herds, even though chronic diseases, such as brucellosis, are contagious and have the potential to cause fertility problems in the herd.
Hope for the chronically sick whose benefits have been withdrawn.
In Dr. Tarr's experience, fat dogs almost always belong to fat masters; neurotic dogs have neurotic masters, chronically sick dogs have chronically sick masters.
They're like chronically sick patients who refuse to take their medication.
A chronically sick child damages an entire family's chances of recovery.
The hidden hand of the market renders invisible the old, the poor, the chronically sick and the long-term disabled.
"I am chronically sick and chronically unemployed and without any specific plan about how to proceed next".
Jo Cole, in Stockton-On-Tees, says: "You are simply not allowed to be chronically sick or disabled any more.
Chronically sick benefit claimants will no longer be required to prove they are still ill every six months, the work and pensions secretary has announced.
A few teaching hospitals have also found they can make chronically sick patients healthier and reduce their costs by giving them 24-hour access to doctors at home.
