Methodology in longitudinal studies on psychological effects of predictive DNA testing: a review

Exploring the short-term impact of DNA-testing in breast cancer patients: the counselees' perception matters, but the actual BRCA1/2 result does not

OBJECTIVE

Previous studies suggest that learning a DNA-test-result has no direct impact on the medical-decisions and psychological well-being of counselees. Their perception, especially their recollections and interpretations of their cancer-risks and heredity, predict and/or mediate this impact. These studies were criticized for their small range of predictors, mediators, outcomes and contextual factors. We studied the short-term impact of DNA-testing with an extended model.

METHODS

Three months after disclosure of BRCA1/2-test-results, we sent counselees a questionnaire about their perception, medical and psychological outcomes, and medical, familial and psychological contexts. 248 affected women participated; 30 had received pathogenic-mutations, 16 unclassified-variants and 202 uninformative-results.

RESULTS

The actually communicated genetic-information and the contextual variables predicted the counselees' perception, but did not directly predict any outcomes. The counselees' perception predicted and/or completely mediated the counselees' medical intentions and behavior, physical and psychological life-changes, stigma, mastery, negativity and cancer-worries. Short-term distress was related to the perception not only of their own risks, but also of their relatives' risks and heredity-likelihood. Effect sizes were medium to large.

CONCLUSIONS AND IMPLICATIONS

The outcomes of DNA-testing were better predicted by the counselees' perception than by the actually given genetic-information. We recommend genetic-counselors to have tailored, interactive dialogues about the counselees' perception.

Testing healthy immigrant effects among late life immigrants in the United States: using multiple indicators

OBJECTIVE

This study tested a healthy immigrant effect (HIE) and postimmigration health status changes among late life immigrants.

METHODS

Using three waves of the Second Longitudinal Study of Aging (1994-2000) and the linked mortality file through 2006, this study compared (a) chronic health conditions, (b) longitudinal trajectories of self-rated health, (c) longitudinal trajectories of functional impairments, and (d) mortality between three groups (age 70+): (i) late life immigrants with less than 15 years in the United States (n = 133), (ii) longer term immigrants (n = 672), and (iii) U.S.-born individuals (n = 8,642). Logistic and Poisson regression, hierarchical generalized linear modeling, and survival analyses were conducted.

RESULTS

Late life immigrants were less likely to suffer from cancer, had lower numbers of chronic conditions at baseline, and displayed lower hazards of mortality during the 12-year follow-up. However, their self-rated health and functional status were worse than those of their counterparts over time.

CONCLUSION

A HIE was only partially supported among older adults.

Longitudinal changes in access to health care by immigrant status among older adults: the importance of health insurance as a mediator

PURPOSE

This longitudinal study examined the role of health insurance in access to health care among older immigrants.

DESIGN AND METHODS

Using data from the Second Longitudinal Study of Aging, the longitudinal trajectories of having a usual source of care were compared between 3 groups (all 70+ years): (a) late-life immigrants with less than 15 years of residence in the United States ("recent immigrants"; n = 133), (b) "earlier immigrants" (15 years or longer in the United States, n = 672), and (c) U.S. born (n = 8,642). A series of hierarchical generalized linear models were run to test the mediating relationship of health insurance between immigrant status and having a usual source of care.

RESULTS

Although the probabilities of having a usual source of care increased over time across all three groups, recent immigrants were less likely to have Medicare and private insurance over time; this in turn was related to lower probabilities of having a usual source of care (indirect relationship). There was no direct relationship between immigrant status and having a usual source of care.

IMPLICATIONS

To prevent the use of more expensive forms of care in the long run, policy efforts should expand late-life immigrants' health insurance coverage by increasing affordable health insurance options.

Psychological and cancer-specific distress at 18 months post-testing in women with demonstrated BRCA1 mutations for hereditary breast/ovarian cancer

AIM

The aim of this longitudinal study was to explore both levels of and factors predictive of psychological and cancer-specific distress in women with demonstrated BRCA1 mutations belonging to families with hereditary breast/ovarian cancer (HBOC).

METHODS

We included 214 women from HBOC families who had BRCA1 testing, and who were examined with a mailed questionnaire at pre-test (T1), 6 weeks after getting the test result (T2) and 18 months later (T3). Self-rating instruments for psychological distress, cancer-specific distress and personality traits were used.

RESULTS

Hardly any significant changes were observed concerning the levels of psychological and cancer-specific distress from T1 via T2 to T3 for the total group or those with carrier or non-carrier status, while women with cancer had a significant reduction of cancer-specific distress over time. The pre-test levels of psychological and cancer-specific distress were significant and strong predictors of these types of distress at T3. The personality trait of neuroticism made a significant contribution to both types of distress at pre-test, and a small separate contribution to distress at T3. Carrier status, history of personal cancer, pre-test levels of optimism or multidimensional health locus of control did not significantly predict distress at T3.

CONCLUSIONS

Genetic testing or test results were not found to induce psychological or cancer-specific psychological distress at long-term. Neuroticism had a decisive influence at both pre-test and long-term levels of distress.

Depression and Suicidal Ideation After Predictive Testing for Huntington's Disease: A Two-Year Follow-up Study

The present study reports a two-year follow-up of psychological effects of predictive testing for Huntington's disease. Questionnaires assessing depression, general health, well-being, self injurious behavior, life satisfaction, and lifestyle were completed by 35 carriers and 58 non-carriers before the predictive test, and 2, 6, 12, and 24 months afterwards. Both carriers and non-carriers showed high suicidal ideation before the predictive testing. Depression scores and frequency of suicidal thoughts increased for carriers, compared to non-carriers, over time. There were no differences regarding life satisfaction or life style between carriers and non-carriers. Predictive testing was beneficial in reducing overall ill-health symptoms and increasing well-being for those initially expressing concern about Huntington's disease. The importance of assessing suicidal ideation and of continuing to provide adequate support is emphasized.

Comparison of genotypic and phenotypic strategies for population screening in hemochromatosis: assessment of anxiety, depression, and perception of health

PURPOSE

Hemochromatosis is a treatable disorder with a major genetic predisposition. It provides an example in which genotypic and phenotypic strategies for screening may be compared. We previously showed noninferiority of uptake of a genotypic population screening strategy for hemochromatosis compared with a phenotypic strategy. In this article we present the psychologic effects of each strategy.

METHODS

A sample of 3000 individuals from primary care were randomly allocated to a phenotypic or genotypic screening strategy for hemochromatosis, and the 939 individuals who accepted screening provide the sample for this article. Standardized assessments of anxiety, general health, and depression were made at invitation, testing, result-giving, and 6 months.

RESULTS

Screening did not lead to significant changes in the self-rated assessments of anxiety, depression, and general health over time, and there were no significant differences between the two screening strategies. The unemployed or permanently disabled had lower ratings of health and higher anxiety and depression.

CONCLUSION

The two screening strategies appeared to cause little adverse psychologic disturbance in the short term, and there was no difference between the two strategies This study provides some empiric data to support arguments against "genetic exceptionalism" and suggests that genetic testing when used for population screening for a treatable disease has few adverse effects.

Psychological impact of genetic testing for hereditary non-polyposis colorectal cancer

The psychological impact of predictive genetic testing for hereditary non-polyposis colorectal cancer (HNPCC) was assessed in 114 individuals (32 carriers and 82 non-carriers) attending familial cancer clinics, using mailed self-administered questionnaires prior to, 2 weeks, 4 months and 12 months after carrier status disclosure. Compared to baseline, carriers showed a significant increase in mean scores for intrusive and avoidant thoughts about colorectal cancer 2 weeks (t = 2.49; p = 0.014) and a significant decrease in mean depression scores 2 weeks post-notification of result (t = -3.98; p < 0.001) and 4 months post-notification of result (t = -3.22; p = 0.002). For non-carriers, significant decreases in mean scores for intrusive and avoidant thoughts about colorectal cancer were observed at all follow-up assessment time points relative to baseline. Non-carriers also showed significant decreases from baseline in mean depression scores 2 weeks, 4 months and 12 months post-notification. Significant decreases from baseline for mean state anxiety scores were also observed for non-carriers 2 weeks post-notification (t = -3.99; p < 0.001). These data indicate that predictive genetic testing for HNPCC leads to psychological benefits amongst non-carriers, and no adverse psychological outcomes were observed amongst carriers.