Do hypnotic drugs cause cancer, like cigarettes?

Sleep disorders and cancer incidence: examining duration and severity of diagnosis among veterans

Introduction

Sleep disruption affects biological processes that facilitate carcinogenesis. This retrospective cohort study used de-identified data from the Veterans Administration (VA) electronic medical record system to test the hypothesis that patients with diagnosed sleep disorders had an increased risk of prostate, breast, colorectal, or other cancers (1999-2010, N=663,869). This study builds upon existing evidence by examining whether patients with more severe or longer-duration diagnoses were at a greater risk of these cancers relative to those with a less severe or shorter duration sleep disorder.

Methods

Incident cancer cases were identified in the VA Tumor Registry and sleep disorders were defined by International Classification of Sleep Disorder codes. Analyses were performed using extended Cox regression with sleep disorder diagnosis as a time-varying covariate.

Results

Sleep disorders were present among 56,055 eligible patients (8% of the study population); sleep apnea (46%) and insomnia (40%) were the most common diagnoses. There were 18,181 cancer diagnoses (41% prostate, 12% colorectal, 1% female breast, 46% other). The hazard ratio (HR) for a cancer diagnosis was 1.45 (95% confidence interval [CI]: 1.37, 1.54) among those with any sleep disorder, after adjustment for age, sex, state of residence, and marital status. Risks increased with increasing sleep disorder duration (short [<1-2 years] HR: 1.04 [CI: 1.03-1.06], medium [>2-5 years] 1.23 [1.16-1.32]; long [>5-12 years] 1.52 [1.34-1.73]). Risks also increased with increasing sleep disorder severity using cumulative sleep disorder treatments as a surrogate exposure; African Americans with more severe disorders had greater risks relative to those with fewer treatments and other race groups. Results among patients with only sleep apnea, insomnia, or another sleep disorder were similar to those for all sleep disorders combined.

Discussion

The findings are consistent with other studies indicating that sleep disruption is a cancer risk factor. Optimal sleep and appropriate sleep disorder management are modifiable risk factors that may facilitate cancer prevention.

External adjustment of unmeasured confounders in a case-control study of benzodiazepine use and cancer risk

AIMS

Previous studies have reported diverging results on the association between benzodiazepine use and cancer risk.

METHODS

We investigated this association in a matched case-control study including incident cancer cases during 2002-2009 in the Danish Cancer Registry (n = 94 923) and age- and sex-matched (1:8) population controls (n = 759 334). Long-term benzodiazepine use was defined as ≥500 defined daily doses 1-5 years prior to the index date. We implemented propensity score (PS) calibration using external information on confounders available from a survey of the Danish population. Two PSs were used: The error-prone PS using register-based confounders and the calibrated PS based on both register- and survey-based confounders, retrieved from the Health Interview Survey.

RESULTS

Register-based data showed that cancer cases had more diagnoses, higher comorbidity score and more co-medication then population controls. Survey-based data showed lower self-rated health, more self-reported diseases, and more smokers as well as subjects with sedentary lifestyle among benzodiazepine users. By PS calibration, the odds ratio for cancer overall associated with benzodiazepine use decreased from 1.16 to 1.09 (95% confidence interval 1.00-1.19) and for smoking-related cancers from 1.20 to 1.10 (95% confidence interval 1.00-1.21).

CONCLUSION

We conclude that the increased risk observed in the solely register-based study could partly be attributed to unmeasured confounding.

Benzodiazepines are Prescribed More Frequently to Patients Already at Risk for Benzodiazepine-Related Adverse Events in Primary Care

BACKGROUND

Benzodiazepine use is associated with adverse drug events and higher mortality. Known risk factors for benzodiazepine-related adverse events include lung disease, substance use, and vulnerability to fracture.

OBJECTIVE

To determine whether benzodiazepine prescribing is associated with risk factors for adverse outcomes.

DESIGN

Longitudinal cohort study between July 1, 2011, and June 30, 2012.

PARTICIPANTS

Patients who visited hospital- and community-based practices in a primary care practice-based research network.

MAIN MEASURES

Odds ratio of having a target medical diagnosis for patients who received standard and high-dose benzodiazepine prescriptions; rates per 100 patients for outpatient and emergency department visits and hospitalizations.

KEY RESULTS

Among 65,912 patients, clinicians prescribed at least one benzodiazepine to 15 % (9821). Of benzodiazepine recipients, 5 % received high doses. Compared to non-recipients, benzodiazepine recipients were more likely to have diagnoses of depression (OR, 2.7; 95 % CI, 2.6-2.9), substance abuse (OR, 2.2; 95 % CI, 1.9-2.5), tobacco use (OR, 1.7; 95 % CI, 1.5-1.8), osteoporosis (OR, 1.6; 95 % CI, 1.5-1.7), chronic obstructive pulmonary disease (OR, 1.6; 95 % CI, 1.5-1.7), alcohol abuse (OR, 1.5; 95 % CI, 1.3-1.7), sleep apnea (OR, 1.5; 95 % CI, 1.3-1.6), and asthma (OR, 1.5; 95 % CI, 1.4-1.5). Compared to low-dose benzodiazepine recipients, high-dose benzodiazepine recipients were even more likely to have certain medical diagnoses: substance abuse (OR, 7.5; 95 % CI, 5.5-10.1), alcohol abuse (OR, 3.2; 95 % CI, 2.2-4.5), tobacco use (OR, 2.7; 95 % CI, 2.1-3.5), and chronic obstructive pulmonary disease (OR, 1.5; 95 % CI, 1.2-1.9). Benzodiazepine recipients had more primary care visits per 100 patients (408 vs. 323), specialist outpatient visits (815 vs. 578), emergency department visits (47 vs. 29), and hospitalizations (26 vs. 15; p < .001 for all comparisons).

CONCLUSIONS

Clinicians prescribed benzodiazepines and high-dose benzodiazepines more frequently to patients at higher risk for benzodiazepine-related adverse events. Benzodiazepine prescribing was associated with increased healthcare utilization.