Performing tests at the point of care (POC) rather than an offsite lab provides faster test results reporting while eliminating the need for specimen transport and other pre-testing processes. POC tests can be administered by physicians and others without primary training in clinical laboratory sciences and, sometimes, even the patients themselves, using kits purchased over the counter without a prescription. This potent combination of speed, convenience, and lower costs has driven significant growth in POC testing.
The tradeoff is that POC tests carry a higher risk of inaccurate results. Things that can go wrong include:
- Improper storage of reagents;
- Incorrect sample collection;
- Not using enough of the sample; and
- Over- or under-timing test development.
For over a decade, the American Association for Clinical Chemistry (AACC) has been a leading source of guidance for safe, proper, and effective use of POC tests. On Aug. 29, the AACC revised its guidelines for POC fertility and reproductive tests.
POC Ovulation Testing
Urine luteinizing hormone (LH) tests “are accurate and reliable predictors of ovulation” that can help “healthy fertile women” improve their chances of conception. LH tests may also be useful in timing certain assisted reproduction procedures. However, the guidelines caution that “further study is needed to determine the efficacy” of basal body temperature (BBT) and saliva at-home ovulation prediction kits.
POC hCG Pregnancy Testing
The rapid rise in beta-human chorionic gonadotropin (hCG) protein serum levels after conception is an early biomarker of pregnancy. The guidelines recommend considering the use of POC as an alternative to lab hCG testing “in clinical situations where rapid diagnosis of pregnancy is needed for treatment decisions and laboratory analysis cannot meet the required turnaround time.” Examples: A positive urine or whole blood POC hCG combined with ultrasound might be appropriate in acute settings for patients with unstable vital signs and symptoms of ruptured ectopic pregnancy requiring immediate intervention.
POC Premature Rupture of Membranes Testing
Premature rupture of membranes (PROM) that can threaten a pregnancy is detected via observation of pooled amniotic fluid, pH testing of vaginal and amniotic fluid, and microscopic analysis revealing ferning patterns in dried vaginal fluid. Most cases of PROM can be diagnosed via “physical examination, clinical presentation, and patient history,” according to the guidelines. PROM testing using commercial kits alone is not recommended unless there are clinical signs that a patient’s water has broken. In addition, “results from these tests must be interpreted in the context of a patient’s clinical presentation to prevent patient harm.” There have also been “reports of misuse resulting in death and health complications for fetus and/or mother,” the guidelines caution.
For a more in-depth report, see this article from the December 2022 issue of Diagnostic Testing & Emerging Technologies, posted in advance of PDF publication.