A research study on genetic diagnostic testing found that many patients did not undergo testing due to the cost of genetic testing. In addition, other reasons to decline testing including a lack of patient interest/availability, patients not following-up on the test, or the test was not needed. According to the researchers, there may be “little published on the clinical experience of patients in such clinics”. However, the rate of testing may improve once approved treatments become available. In a study in the University of Arkansas, a total of 304 patients were evaluated and of these, only 54% of patients went on to complete genetic testing. Further categorizing reasons for not undergoing genetic testing will be important to develop strategies to encourage patients to pursue the genetic diagnostic testing.
In the analysis of the study, the results showed that of the 304 patients, the most common reasons for declining the genetic testing included referring diagnoses for retinal dystrophy (62 patients), retinitis pigmentosa (55 patients), albinism (25 patients), and Stargardt disease (13 patients). For those referrals followed up, 164 patients of 304 had testing performed and completed.
| Primary Referring Diagnosis | Suspected cases | Testing performed and completed | Testing was diagnostic |
| Retinal Dystrophy | 62 | 34 | 11 |
| Retinitis Pigmentosa | 55 | 35 | 13 |
| Ocular Albinism/ Oculocutaneous/ Albinism | 25 | 13 | 6 |
| Stargardt Disease | 13 | 6 | 5 |
| Macular Dystrophy | 10 | 3 | 1 |
| Optic Atrophy | 9 | 6 | 1 |
| Leber Congenital Amaurosis | 7 | 4 | 1 |
| Leber Hereditary Optic Neuropathy | 6 | 4 | 3 |
| Rod-Cone Dystrophy | 6 | 1 | 0 |
| Usher Syndrome | 5 | 5 | 3 |
| Other Diagnoses (77 different diagnoses) | 106 | 53 | 15 |
| Total | 304 | 164 | 59 |
Collected data from the research indicated that of the 46% of patients who did not get testing, approximately 59% declined testing for financial reasons – for either insurance costs were declined to cover the test, or that prior authorizations were not completed/not completed correctly. A further 24% of patients were not interested in the genetic diagnostics, while 14% of patients did not get testing, possibly ruled out the disease for which the patient was referred. Finally, “3% declined testing because a different sibling had already been tested and the parents did not want to pursue further testing in their other children”. One limitation of the study showed that the categorization of the field may be a problem due to the original database construction, as commented on by the researchers, “when the database was originally constructed, the developers did not make a standardized menu of choices of reasons to forgo testing.” Consequently, there is a gap in the information available to understand how patients specifically identify the reasons not to progress with the genetic diagnostic testing. The study’s authors conclude that, “it will be interesting to see how this issue changes in the future as genetic testing becomes more robust and cheaper, and as more effective treatments are developed”.