Reasonable minds can disagree over this. If a claimant prevails at the initial level, then, by definition, he did not need an attorney. The question arises, if the claimant lost at the initial level, might he have prevailed if he had a lawyer? The answer to this question is somewhat elusive as it is difficult to say unless you know the facts of the case and what the screener wanted to see. Not all screeners are created equal.
Some lawyers provide lengthy medical summaries and arguments as to why a claimant should win along with the initial application. If these documents are read, then the information is helpful--possibly. Cases that prevail at the initial level are usually those that win on their face. They don't need to be explained. They are essentially self-evident.
Most claimants should try and file on their own the first time and see what happens. It is very likely they will be turned down. I do think, however, it does not hurt to talk to a lawyer before filing. Many of my clients talked to me before filing, but they did not retain me until after the initial denial. Quite frankly, the best news I can get is when I told a claimant to file, and the claimant gets disability without my help or my contingency fee.