Subjective cognitive decline and risk of MCI: The Mayo Clinic Study of Aging

OBJECTIVE

We investigated different dimensions of subjective cognitive decline (SCD) to determine which was the best prognostic risk factor for incident mild cognitive impairment (MCI) among cognitively unimpaired participants.

METHODS

We included 1,167 cognitively unimpaired participants, aged 70 to 95 years, from the Mayo Clinic Study of Aging based on 2 concurrent SCD scales (part of the Blessed memory test and the 39-item Everyday Cognition [ECog] scale, which included a validated 12-item derivative) and a single question assessing worry about cognitive decline. We evaluated multiple ways to dichotomize scores. In continuous models, we compared average scores on 4 ECog domains and multidomain (39- and 12-item) ECog scores. Cox proportional hazards models were used to assess the association between each measure and risk of MCI in models adjusted for objective memory performance, depression, anxiety, sex, APOE ε4 carriership, and medical comorbidities.

RESULTS

It was possible to select a substantial group of participants (14%) at increased risk of incident MCI based on combined baseline endorsement of any consistent SCD on the ECog (any item scored ≥3; 12-item ECog hazard ratio [HR] 2.17 [95% confidence interval 1.51-3.13]) and worry (HR 1.79 [1.24-2.58]) in an adjusted model combining these dimensions. In continuous models, all ECog domains and the multidomain scores were associated with risk of MCI with a small advantage for multidomain SCD (12-item ECog HR 2.13 [1.36-3.35] per point increase in average score). Information provided by the informant performed comparable to self-perceived SCD.

CONCLUSION

Prognostic value of SCD for incident MCI improves when both consistency of SCD and associated worry are evaluated.

Indicators of amyloid burden in a population-based study of cognitively normal elderly

OBJECTIVES

Secondary prevention trials in subjects with preclinical Alzheimer disease may require documentation of brain amyloidosis. The identification of inexpensive and noninvasive screening variables that can identify individuals who have significant amyloid accumulation would reduce screening costs.

METHODS

A total of 483 cognitively normal (CN) individuals, aged 70-92 years, from the population-based Mayo Clinic Study of Aging, underwent Pittsburgh compound B (PiB)-PET imaging. Logistic regression determined whether age, sex, APOE genotype, family history, or cognitive performance was associated with odds of a PiB retention ratio >1.4 and >1.5. Area under the receiver operating characteristic curve (AUROC) evaluated the discrimination between PiB-positive and -negative subjects. For each characteristic, we determined the number needed to screen in each age group (70-79 and 80-89) to identify 100 participants with PiB >1.4 or >1.5.

RESULTS

A total of 211 (44%) individuals had PiB >1.4 and 151 (31%) >1.5. In univariate and multivariate models, discrimination was modest (AUROC ∼0.6-0.7). Multivariately, age and APOE best predicted odds of PiB >1.4 and >1.5. Subjective memory complaints were similar to cognitive test performance in predicting PiB >1.5. Indicators of PiB positivity varied with age. Screening APOE ε4 carriers alone reduced the number needed to screen to enroll 100 subjects with PIB >1.5 by 48% in persons aged 70-79 and 33% in those aged 80-89.

CONCLUSIONS

Age and APOE genotype are useful predictors of the likelihood of significant amyloid accumulation, but discrimination is modest. Nonetheless, these results suggest that inexpensive and noninvasive measures could significantly reduce the number of CN individuals needed to screen to enroll a given number of amyloid-positive subjects.

Impact of an occupational and environmental medicine curriculum on lost workdays

OBJECTIVE

We established an occupational and environmental medicine (OEM) curriculum for our residents. We hypothesized that greater OEM knowledge would decrease the number of lost workdays for injured patients.

METHODS

We retrospectively compared return-to-work outcomes before and after implementation of the OEM curriculum. Study subjects were workers' compensation patients (18 years and older) seen between January 1, 2001, and December 31, 2002.

RESULTS

In 2001, 253 injured workers were treated; in 2002, 204 were treated. The OEM curriculum was introduced in January 2002. The adjusted odds ratio for having lost workdays increased after implementation of the curriculum.

CONCLUSIONS

Greater competence in assessment and treatment of occupational injuries may increase lost work time for injured patients. This surprising result was a cause for concern. However, by including only patients with injuries in the analysis, it is unlikely that this paradoxical result was attributable to increased recognition of occupational disease. Treatment by the employee's personal physician may have had an effect on the number of lost workdays.

CLINICAL SIGNIFICANCE

In an effort to reduce lost workdays for the injured employee, we implemented a formal OEM curriculum for family medicine residents at our clinic. The curriculum and results are presented in this article.

Innovative Reflecting Interview: Effect on High-Utilizing Patients with Medically Unexplained Symptoms

This pilot study was conducted to determine the effect of an innovative reflecting interview on the health care utilization, physical health, mental function, and health care satisfaction of high-utilizing primary care patients with medically unexplained physical symptoms. Twenty-four high-utilizing patients met study selection criteria and were randomly assigned to a no-intervention control group or a reflecting interview intervention group. Outcomes were measured at 4 weeks, 6 months, and 1 year after the date of study enrollment. Results indicated that high-utilizing patients with medically unexplained physical symptoms who participated in a reflecting interview had reduced total health care costs, primarily through the reduction of hospitalization or inpatient expenses, despite a modest increase in outpatient primary care clinic visits. These data suggest that participation in a reflecting interview and regular visits with a primary care clinician can decrease health care utilization without adversely affecting patient satisfaction.