The Houston Chronicle reports that the rise of walk-in clinics at retail outlets and expanded government prescription drug coverage to seniors may be responsible for the shrinking number of patients at the Harris County Hospital District in Texas, which serves as the health care safety net for nearly a third of the county's 3.8 million uninsured residents.

District officials pointed to the increasing popularity of in-store clinics that have sprouted at Wal-Marts, CVS stores and retail outlets across the city and nation as a possible source of patient drain. The in-store clinics allow patients to get treated, without an appointment, by physician's assistants and nurse practitioners for minor ailments.

Patients who use the district's community health clinics do not receive same-day service, often waiting two weeks to be seen.

Another possible cause of the shrinking patient load may be the changes in Medicare prescription drug coverage that took effect two years ago. Before Medicare Part D began, senior citizens without prescription coverage could get medicines when they were treated at district facilities. Now, senior citizens who can get medications at any drug store through Medicare Part D are choosing other health care providers over the district's doctors.