It's 'useless' trying to change her mind. = It's 'useless' to try to change her mind.
Drugs are 'useless' in treating the condition.
I made a 'useless' attempt at fixing the leak.
(..) because Nadya's parents won't let her set foot in the house. And who can blame them? It's indecent. It's Konstantin. Yes, good. The doctor here is useless. Get me one from Moscow. Where did you go? I asked for you everywhere when I was getting married. I'm sorry. I couldn't leave him. (..)2012 Anna Karenina