Validation of Self-Reported Cancer Diagnoses by Respondent Cognitive Status in the U.S. Health and Retirement Study

BACKGROUND

Cancer and dementia are becoming increasingly common co-occurring conditions among older adults. Yet, the influence of participant cognitive status on the validity of self-reported data among older adults in population-based cohorts is unknown. We thus compared self-reported cancer diagnoses in the U.S. Health and Retirement Study (HRS) against claims from linked Medicare records to ascertain the validity of self-reported diagnoses by participant cognitive and proxy interview status.

METHODS

Using data from HRS participants aged ≥67 who had at least 90% continuous enrollment in fee-for-service Medicare, we examined the validity of self-reported first incident cancer diagnoses from biennial HRS interviews against diagnostic claim records in linked Medicare data (reference standard) for interviews from 2000 to 2016. Cognitive status was classified as normal, cognitive impairment no dementia (CIND), or dementia using the Langa-Weir method. We calculated the sensitivity, specificity, and κ for cancer diagnosis.

RESULTS

Of the 8 280 included participants, 23.6% had cognitive impairment without dementia (CIND) or dementia, and 10.7% had a proxy respondent due to an impairment. Self-reports of first incident cancer diagnoses for participants with normal cognition had 70.2% sensitivity and 99.8% specificity (κ = 0.79). Sensitivity declined substantially with cognitive impairment and proxy response (56.7% for CIND, 53.0% for dementia, 60.0% for proxy respondents), indicating poor validity for study participants with CIND, dementia, or a proxy respondent.

CONCLUSIONS

Self-reported cancer diagnoses in the U.S. HRS have poor validity for participants with cognitive impairment, dementia, or a proxy respondent. Population-based cancer research among older adults will be strengthened with linkage to Medicare claims.

Sensitivity and specificity of self-reported psychiatric diagnoses amongst patients treated for opioid use disorder

BACKGROUND

Patients with opioid use disorder (OUD) frequently present with comorbid psychiatric illnesses which have significant implications for their treatment outcomes. Notably, these are often identified by self-report. Our study examined the sensitivity and specificity of self-reported psychiatric diagnoses against a structured diagnostic interview in a cohort of patients receiving outpatient pharmacological treatment for OUD.

METHODS

Using cross-sectional data from adults receiving outpatient opioid agonist treatment for OUD in clinics across Ontario, Canada, we compared participants' self-reported psychiatric diagnoses with those identified by the Mini Neuropsychiatric Interview (MINI) Version 6.0 administered at the time of study entry. Sensitivity and specificity were calculated for self-report of psychiatric diagnoses.

RESULTS

Amongst a sample of 683 participants, 24% (n = 162) reported having a comorbid psychiatric disorder. Only 104 of these 162 individuals (64%) reporting a comorbidity met criteria for a psychiatric disorder as per the MINI; meanwhile, 304 (75%) participants who self-reported no psychiatric comorbidity were in fact identified to meet MINI criteria for a psychiatric disorder. The sensitivity and specificity for any self-reported psychiatric diagnoses were 25.5% (95% CI 21.3, 30.0) and 78.9% (95% CI 73.6, 83.6), respectively.

CONCLUSIONS

Our findings raise questions about the utility of self-reported psychiatric comorbidity in patients with OUD, particularly in the context of low sensitivity of self-reported diagnoses. Several factors may contribute to this including remittance and relapse of some psychiatric illnesses, underdiagnosis, and the challenge of differentiating psychiatric and substance-induced disorders. These findings highlight that other methods should be considered in order to identify comorbid psychiatric disorders in patients with OUD.