The phrase "at worst when" is not correct and does not convey a clear meaning in written English.
It may be intended to express a situation that is at its most negative or unfavorable during a specific time, but the construction is awkward.
Example: "At worst when the weather is bad, we can still find indoor activities to enjoy."
Alternatives: "at the very least" or "in the worst-case scenario".
At worst, when the treatment is used as an alternative for (untrendy, Western) methods it can be downright dangerous.
At least in my experience, these cry analyzers are at best novel curiosities, and at worst — when your baby is screaming uncontrollably and you're at wit's end — frustrating time-wasters.
May said that at best stop and search applied fairly could lead to arrests and build community confidence in the police but at worst when it was misapplied it undermined public confidence and wasted police time.
All of this frequently adds up to confusion at best, and hostility at worst, when people encounter butch lesbians.
We'll give Smith's staff the benefit of the doubt on this, and assume they're being disingenuous at worst when they profess not to know his press release was nothing like the truth, the whole truth, and nothing but the truth.
At its worst, when he was exploding at school and hardly speaking to us at home, it seemed as though he was afflicted with this thing we've named autism.
The City is at its worst when it is looking at sepia photographs of how good it thought it was.
The problem is at its worst when technology is discovered at a university and licensed to a single biotech, Collins says.
In fact suicides in Greenland are at their worst when the sun comes back at the end of winter.
They were at their best and most glamorous with straight dance records such as Van McCoy's "The Hustle", and at their worst when they had to dance along with an ill-at-ease Georgie Fame ina nightshirt singing "Seventh Son", surely the strangest production of a blues song ever shown on television.
Arnold is at his best when he's being humorous, at his worst when he has to explain a position in detail".
