The patients visited Dr. Raman only when things looked hopeless because they couldn't afford his high fees and also because they felt that his presence would jinx their probability of survival.
Basically, these superstitious patients believed that Dr. Raman's presence at their bedside would result in certain death. It's a vicious cycle. First, patients neglected calling on Dr. Raman because they couldn't afford his fees. So, they usually waited until their cases were hopeless. Then, and only then, did they call on Dr. Raman, as a last-ditch effort to save themselves.
However, the time factor usually proved fatal: patients who waited too long to get the care they needed often died. Because Dr. Raman usually presided over these deaths, he began to get the unenviable reputation of being a sort of jinx.
We see this in the story, when Gopal's wife makes her excuses for not calling on Dr. Raman. Accordingly, Gopal has been bedridden for one and a half months. Gopal's wife is visibly embarrassed when Dr. Raman asks her why they have neglected to alert him to Gopal's condition. She stammers that neither she nor Gopal wanted to inconvenience Dr. Raman. However, the truth is that, like many others, they couldn't afford his fees and didn't want to jinx Gopal's chances of survival. Through denial, they had hoped to preserve the facade that Gopal was merely sick and not dying.