A middle aged patient with no health insurance and a well documented history of moderate to severe bipolar disorder visits a low cost clinic.
The patient has a just lapsed lithium prescription and cannot get a refill directly at a pharmacy. The patient needs a new prescription for lithium, and this is the reason for the visit.
The health care provider would like to draw blood to test renal function.
Unfortunately, lab tests are not provided free, and the cost of the blood test is outside of the reach of the patient. A urine test is also too expensive.
There is more than one patient with this situation.
Is there an alternative method(without lab tests) that can assess whether the prescription can be safely filled?
Assume there is one doctor/physician assistant/nurse practitioner donating time.