DEERFIELD, Ill. -- Drugstores are expanding their health services at in-store clinics to include cholesterol and blood glucose testing, blood pressure screening, vitamin B-12 injections and some vaccines, such as HPV, shingles and whopping cough, Marketing Daily reports.

The changes are part of an effort to boost usage of retail clinics, which have seen sales climb 81 percent annually since 2005. This year, sales are predicted to reach $733.4 million, according to Kalorama Information. In-store clinics are "likely to become a durable part of the health-care system," said the research firm in its report, adding that the rate of new locations has become sluggish.

Despite the rocky economy, retail clinics have continued to grow, even though some state governments have tried to curb their offerings. "For example, Florida limits a physician to supervising only one clinic, while North Carolina??s law restricts physicians to two supervisees, which could have the same effect," the Kalorama Information report read.

"These laws could go to the heart of the retail clinic concept, which is that some cost savings will come from using nurse practitioners instead of physicians. Massachusetts has regulated what conditions can be treated in clinics and limits immunizations of children to flu shots only. New York State is investigating whether retail clinics steer customers toward the in-store pharmacy, and is among several states considering a ban on tobacco sales where a retail location has a clinic," the report stated.