Although the Great Recession ended nearly six years ago, many small business owners still feel their companies haven't recovered.

That's the finding of a survey released Wednesday by Bank of America. Nearly two-thirds of the owners questioned last month said they're still in recovery mode. Only 21 percent said their companies have completely recovered.

The fact that so many owners still feel like they're trying to get their business back to pre-recession levels helps explain their reluctance to hire. Employment growth at small businesses has remained low even as the overall economy has picked up since the recession ended in June 2009.

Owners remain cautious about hiring, with 39 percent questioned in the survey saying they plan to add staffers in the next 12 months. That's down from 42 percent in a survey during the fall. Just over half plan to keep staffing levels where they are now, slightly more than in the previous survey.

Asked about their concerns, 58 percent said consumer spending that has slowed recently could affect their companies. Health care costs are also a concern, cited by 65 percent.

But owners are upbeat. Fifty-nine percent said they expect their revenue to grow during the next 12 months, and 31 percent expect revenue to be stable.

Owners' outlook and hiring plans are in line with other surveys that have shown them to be generally optimistic but still conservative. Many owners came out of the recession with less of an appetite for risk, including taking on debt and hiring workers before they had the revenue to justify the staff additions.

The survey questioned 1,000 small business owners.