SAUSALITO - The internet era, the shortage of doctors in many parts of the country, and the lack of health care insurance have created a new era of "urgent care light" as patients get tired of waiting days for medical attention, and those without health insurance run to local drug stores, discount club pharmacies and mini-care retail clinics where they can have only a brief wait to see a doctor or a nurse, and walk out with a prescription.

Across the country, from California to New York, Boston, and down to Florida and Texas, thousands of retail clinics have opened over the past two years, including the popular chain stores at Wal-Mart, Costco, Walgreens, CSV, and Duane Reade. Barring regulation from state health officials, many are anxiously waiting to aggressively open even more clinics and spread into more states.

Patients wanting a basic exam, wart removal, abscess drainage, or treatment for a sprained ankle can pop in and get immediate treatment and often generic prescriptions for as low as $10 at some of the pharmacies.

But with their increasing popularity, the clinics are drawing mounting scrutiny. Several states including New York, New Jersey, Rhode Island, Massachusetts and California are examining ways to more closely monitor the clinics, which are overseen by a hodgepodge of state agencies applying a wide and inconsistent range of regulations.

Regulators are investigating the business relationships between drugstore companies and medical providers to determine whether the clinics are being used improperly to increase business or steer patients to the pharmacies in which the clinics are located.

Doctors? groups, whose members stand to lose business from the clinics, are citing concerns about standards of care, safety and hygiene, and they have urged the federal and state governments to step in to more rigorously regulate the new businesses.

Patients, however, have flocked to the clinics, according to a new industry group, the Convenient Care Association.

The average waiting time for an exam at such clinics nationwide is 15 to 25 minutes, according to the Convenient Care Association.

The association estimated that 70 percent of clinic patients have health insurance and are using the clinics because of convenience. For them, costs may not be much different from those at doctors? offices, because the same insurance co-payments apply. But uninsured patients could reap substantial savings.

MinuteClinic, a wholly owned subsidiary of CVS Caremark, the drug chain?s formal name, and the largest of more than a dozen clinic operators nationwide said it hoped to open as many as 2500 more clinics which would be staffed by nurse practitioners and physician assistants.

In some states, nurse practitioners are required to work closely with a physician, who oversees the practice but is not required to be at the clinic, and that the clinics operate as independent practices or professional corporations. In other states, the medical providers can work directly for a drugstore company, a practice that has touched off concern that the providers might place the interests of their employers above those of patients.

MinuteClinic officials insisted that there was nothing improper in the relationships between providers and the drugstores and that medical care is not being compromised.

We are transparent with regulators,? said Michael C. Howe, the chief executive of MinuteClinic, which is based in Minneapolis and operates more than 200 clinics nationwide. using the motto ?You?re Sick, We?re Quick.?

Howe said their original slogan was changed from, "You're Queer, We're Here" after some anti-gay protests.

Mr. Howe said the concerns of doctors? groups and other critics ?are being raised by voices of people who have not really studied the model.?

Preliminary data from a two-year study of claims from MinuteClinic by a Minnesota health maintenance organization, HealthPartners, which was released to The Minneapolis Star Tribune in July, showed that each visit to the retail clinic cost an average of $18 less than a visit to other primary-care clinics, but that pharmacy costs were $4 higher per patient.

Duane Reade, a large drugstore chain, plans to aggressively open more clinics as well. A key difference at the Duane Reade clinics is that they use doctors, while nurse practitioners and physician assistants typically provide the care at most retail clinics.

Pediatrician groups have strongly opposed reliance on the clinics because of the importance of having doctors who are familiar with a child?s medical history.

?We are in the embryonic stage of a new era for health care,? a senior vice president stated, ?the traditional place that we deliver care is no longer in the traditional location.?

Doctors? groups said they had fewer objections to doctor-run retail clinics, because the doctors are accountable to a state licensing board.

The pharmacy companies and the operators of the clinics insisted that customers are not told where to fill their prescriptions. But the proximity of the pharmacy is part of the appeal for consumers, and some say they would undoubtedly see increased sales at pharmacies with clinics.