Medicare Part D data: A valuable tool for pharmacoepidemiology and pharmacoeconomic research

Anticholinergic burden and risk of cognitive impairment in elderly nursing home residents with depression

BACKGROUND

Although the adverse cognitive effects of anticholinergic medications in the elderly are well-documented, little is known regarding the cognitive impact of anticholinergics among nursing home residents with depression.

OBJECTIVE

This study examined the risk of mild-to-moderate cognitive impairment due to anticholinergic burden among elderly nursing home residents with depression.

METHODS

A population-based nested case-control study was conducted using Minimum Data Set (MDS)-linked Medicare data where the base cohort included patients ≥ 65 years with depression who had intact cognition (MDS Cognition score of 0 or 1) and no dementia. Cases were identified as those who had mild-to-moderate cognition (MDS Cognition score of 2-4). Each case was matched on age and sex to one control using incidence density sampling. The study evaluated cumulative anticholinergic burden (defined as score of 3 or more) within 30, 60 and 90 days preceding the event date based on the Anticholinergic Drug Scale (ADS). Conditional logistic regression model stratified on matched case-control sets was performed to evalaute cognitive impairment due to cumulative anticholinergic burden after controlling for other risk factors.

RESULTS

The study sample included 3707 cases with mild-to-moderate cognition and 3707 matched controls with intact cognition. Bivariate analysis showed significant association between cumulative anticholinergic exposure and cognitive impairment (Odds Ratio [OR], 1.15; 95% Confidence Interval [CI],1.04-1.30); after controlling for potential risk factors, cumulative anticholinergic exposure 30 days preceding the event was no longer associated with cognitive impairment, (aOR, 1.07; 95% CI, 0.95-1.21). However, the odds of cognitive impairment increased with cumulative anticholinergic exposure 60 days (aOR 1.16; 1.04-1.30) and 90 days (aOR 1.28; 1.14-1.44) before the event date.

CONCLUSION

Cumulative anticholinergic use for prolonged exposure periods was associated with modestly increased risk of cognitive impairment in elderly residents with depression who had intact cognition. The findings suggest the need to be cautious when prescribing multiple anticholinergic drugs in residents, including those with intact cognition.

Risk of Cognitive Decline Associated With Paroxetine Use in Elderly Nursing Home Patients With Depression

OBJECTIVE

This study evaluated the risk of cognitive decline associated with paroxetine use in elderly nursing home patients with depression.

METHODS

A retrospective cohort study was conducted using the 2007 to 2010 Medicare Part D claims and minimum data set (MDS) data involving new users of paroxetine and other selective serotonin reuptake inhibitors (SSRIs). The primary outcome was MDS Cognition Scale. The repeated-measures mixed model was used to examine the effect of paroxetine on cognition after controlling for other factors.

RESULTS

The baseline MDS Cognition Scale measures for paroxetine (n = 63) and other SSRI users (n =1018) were 2.02 (±1.85) and 2.50 (±2.39), respectively. The repeated-measures mixed model did not find statistically significant difference in cognition with the use of paroxetine (β = 0.02, 95% CI: -0.16 to 0.21]) when compared to other SSRIs.

CONCLUSIONS

There was no differential effect of paroxetine on cognition when compared to other SSRIs.

Comparative risk of hip fractures in elderly nursing home patients with depression using paroxetine and other selective serotonin reuptake inhibitors

AIM

To evaluate comparative safety of paroxetine and other selective serotonin reuptake inhibitors (SSRIs) for the risk of hip fractures.

PATIENTS & METHODS

A propensity score-matched retrospective cohort study was conducted using 2007-2010 Minimum Data Set linked Medicare data. Robust Cox proportional hazards model was used to evaluate the risk of hip fractures in depressed elderly nursing home residents.

RESULTS

Cox analysis did not find any significant difference in the risk of hip fractures for the paroxetine users (hazard ratio: 1.09; 95% CI: 0.91-1.32) when compared with other SSRIs. Results from the sensitivity analysis supported the main findings.

CONCLUSION

There was no differential risk of hip fractures between paroxetine and other SSRIs. Future studies are needed to evaluate other anticholinergic effects of paroxetine.

Anticholinergic Medication Use and Risk of Dementia Among Elderly Nursing Home Residents with Depression

OBJECTIVE

To examine the risk of dementia with anticholinergic use among elderly nursing home residents with depression.

DESIGN

Population-based nested case-control study.

SETTING

Population-based study involving 2007-2010 Minimum Data Set-linked Medicare data from all 50 states.

PARTICIPANTS

Medicare beneficiaries aged 65 years and older, diagnosed with depression, and no history of dementia as of 2007 (baseline period). Cases were identified as patients with incident dementia following the baseline period. For each case, four age- and sex-matched control subjects were selected using incidence density sampling.

MEASUREMENTS

Anticholinergic exposure was defined using Anticholinergic Drug Scale. Prescription of clinically significant anticholinergic medications (levels 2 and 3) 30 days preceding the event date formed the primary exposure. The primary outcome was dementia diagnosis, between January 1, 2008, and December 31, 2010. A conditional logistic regression model stratified on matched case-control sets was performed to assess dementia risk, after controlling for other risk factors.

RESULTS

The study sample included 28,388 cases diagnosed with dementia and 113,352 matched control subjects. After adjusting for other risk factors, clinically significant anticholinergic use was associated with significant risk of dementia (OR: 1.26; 95% CI: 1.22-1.29) compared with non-use. The findings remained consistent across levels of anticholinergic potency (level 2, OR: 1.37, 95% CI: 1.31-1.44; level 3, OR: 1.15, 95% CI: 1.10-1.19).

CONCLUSION

Use of clinically significant anticholinergic medications was associated with a 26% increase in risk of dementia among elderly nursing home residents with depression. With increasing safety concerns, there is a significant need to optimize anticholinergic use, especially for those who are at risk for dementia.

Comparative Cognitive Profile of Second-Generation Antidepressants in Elderly Nursing Home Residents With Depression

BACKGROUND

Past literature suggests that the use of second-generation antidepressants improves cognition in depressed elderly patients.

OBJECTIVE

This study assessed the comparative cognitive profile of commonly used second-generation antidepressant classes in elderly residents with depression.

METHODS

A multiple propensity score adjusted retrospective cohort study was conducted using 2007-2010 Medicare Part D claims and Minimum Data Set (MDS). Elderly nursing home residents (65 years or older) with depression using a new prescription of selective serotonin reuptake inhibitors (SSRIs), serotonin-norepinephrine reuptake inhibitors (SNRIs), and tetracyclics constituted the study cohort. The outcome of interest was cognition, measured using the MDS Cognition Scale. Cognition was measured at each quarterly assessment after antidepressant initiation for a maximum of 1 year. The propensity score-adjusted repeated-measures mixed model was used to evaluate the comparative profile of SSRIs, SNRIs, and tetracyclics with respect to cognition.

RESULTS

The study cohort comprised 1518 elderly nursing home residents. Of these, 1081 received SSRIs (71.21%), 320 received tetracyclics (21.08%), and 117 received SNRIs (7.71%). The propensity score-adjusted repeated-measures mixed model did not show any statistically significant difference in cognition with the use of SSRIs (β = -0.14; 95% CI = -0.53, 0.25) or tetracyclics (β = -0.36; 95% CI = -0.80, 0.08) when compared with SNRIs, after controlling for other factors.

CONCLUSIONS

The cognitive effect of SSRIs, SNRIs, and tetracyclics was similar in elderly nursing home residents with depression. Further studies are needed to evaluate the long-term cognitive effects of second-generation antidepressants in this vulnerable population.