Feature Story

Since you asked . . . answers on POC
Checklist clarifications: To each its own—guidelines for point-of-care QC

September 2004
Anne Paxton

There was one simple reason why the CAP Point of Care Testing Committee decided to develop a "Frequently Asked Questions" document for the point-of-care checklist: demand. "Even though POC is really a small piece of the overall testing pie, it’s the subject of up to half of the questions directed to the Laboratory Accreditation Program," says committee member Roger D. Klein, MD, a laboratory medicine resident at Yale. "Basically this project resulted from the many participant questions that were areas of concern or confusion."

Dr. Klein, together with committee chair Peter J. Howanitz, MD, and fellow committee member Sheldon M. Campbell MD, PhD, started by studying several hundred questions that have come in over roughly the past three years. They found many people needed clarification on a broad range of issues.

Questions on physician-performed testing led the pack, along with method-to-method and instrument-to-instrument comparisons. "But there have also been multiple questions on the definition of POC testing, what testing is inspected under the POC checklist, what analytes we have to perform proficiency testing for and under what circumstances, the content of procedure manuals for new instruments—plus lots of questions relating to competency testing. And there were quite a few on calibration verification and analytic measurement range," Dr. Klein says.

"It’s very difficult for a checklist—no matter how hard you try to make it specific—to meet all situations," he notes. "Often the questions would concern some subtlety or some deviation that wasn’t exactly met by the checklist question, and they really reflect the participants’ desire to find out how the checklist applies to their individual situations."

Drs. Klein, Campbell, and Howanitz distilled the questions to 62, then drafted answers and circulated the document within the committee for several rounds of review. "It was a continual work in progress. Though we started with specific questions, we tried to provide a somewhat general spin so the answer would be applicable to a broader range of similar questions."

The committee hopes the resulting "Frequently Asked Questions" document will provide guidance to participants and POC inspectors. "POC really encompasses a broad range of testing, covering many specialties, and the checklist has been an attempt to be somewhat specific in providing guidance," Dr. Klein says.

The "FAQ" project happened to dovetail with another task the committee is charged with: rewriting the POC checklist. "These questions helped stimulate some of the thought process that went into the revision, because there were some lively debates on how things ought to be handled," he says.

"We had standard answers we provided from CAP, and there was a strong consensus, but at times we had differing opinions on how questions ought to be interpreted. I think some discussions prompted by the checklist have resulted in clarifying comments being added to the checklist itself, particularly in the area of physician-performed testing."

The FAQ document is available on CAP’s Web site at POC Introduction. Here is an excerpt of that document.

1. Multiple sites within our hospital perform urine hCG, fecal occult blood, and other POC testing under the same CLIA number. Do we need to enroll in a proficiency survey program for each site that performs POC testing?

   Only one proficiency survey kit is required for each analyte and method that is tested under a given CLIA number. The kits may be rotated among your POC test sites. After reserving an aliquot of PT material for possible followup testing in the event of an unacceptable result on initial testing, you should consider distributing aliquots of the remaining sample to additional test sites. The results of testing at these sites can be compared to the results of your evaluation. Note your performance and any corrective actions that you take.

2. The CAP checklist requires laboratories to define tolerance limits for control procedures. Please explain the meaning of this requirement.

   The CAP POCT checklist requires that laboratories determine appropriate quality control ranges. For unassayed quality control materials, this must be accomplished prior to placing the controls into use. It is preferable to validate manufacturers’ quality control ranges for assayed materials prior to placing new control lots into use. However, for assayed materials this validation may be performed as the control lots are used, if time constraints do not allow for earlier validation. After a laboratory has validated the manufacturer-supplied range for a lot of control materials, the necessity of adjustment to that QC range is within the discretion of the laboratory director.

3. Our hospital uses a significant number of temporary agency nurses. The agency is responsible for training the nurses in the use of our hospital’s POC instruments. Is it acceptable for multiple temporary agency nurses who perform POC glucose testing to use a generic glucose meter user ID#, for example, 55555? Must we retain records of these temporary agency nurses’ glucose meter training?

   The CAP requires that POC testing protocols contain provisions that permit the unique identification of analysts who perform patient testing. The use of a generic identification number that would be shared among multiple instrument users does not allow for the unique identification of testing personnel, and therefore would not meet CAP requirements if used without additional means of uniquely identifying the individual who performs each test.

   The CAP also requires that institutions provide documentation of specific training and competency assessment programs for all employees who perform point-of-care testing. Therefore, you must retain records of the training and competency assessment performed by temporary agencies.

4. Is calibration verification required for ACT instruments?

   Calibration verification is not applicable to coagulation testing that reports patient results in units of time (that is, ACT, PT/INR, APTT).

5. Physicians at our institution frequently perform bedside Hemoccult testing. Do we need to document competency for these physicians? Must we document quality control results for the testing they perform?

   For tests that are included in the physician-performed testing section of the CAP POCT checklist or are FDA-classified waived tests, oversight of physician competency is the responsibility of your medical staff credentialing officials.

   Physician competency assessment for these tests will not be addressed during CAP inspections. Physicians must document quality control for the tests they perform. Specifically, in addition to patient results, daily positive and negative control results should be recorded. A requirement for external controls depends upon the presence of internal controls and manufacturer instructions. Please note that controls must be run as often as the manufacturer requires, but no less frequently than once each patient day. In the case of Hemoccult cards, for example, internal positive and negative controls should be performed with each test card development.

Anne Paxton is a writer in Seattle.