# Actigraphy‑derived multidimensional sleep health among breast cancer survivors and controls: Pink SWAN

## TL;DR

Breast cancer survivors and controls both experience poor sleep health, with shorter sleep duration in survivors within five years of diagnosis.

## Contribution

The study reveals that sleep differences between breast cancer survivors and controls depend on time since diagnosis.

## Key findings

- BCS within 5 years of diagnosis had shorter total sleep time than controls.
- Both BCS and controls showed poor sleep health across multiple dimensions.
- Exogenous hormone and anxiolytic use were more common among BCS.

## Abstract

To compare breast cancer survivors (BCS) to women without breast cancer (controls) on sleep health risk factors and actigraphy-derived dimensions of sleep (duration, maintenance, timing, and regularity) and examine whether the effect of breast cancer on sleep differs by time since diagnosis.

Analyses included data from 68 BCS and 1042 controls who participated in actigraphy and Pink SWAN sub-studies within the Study of Women’s Health Across the Nation. BCS and control characteristics were compared using chi-square, Fisher’s exact, and Wilcoxon rank sum tests. Sleep measures were regressed onto breast cancer status using binomial logistic and linear regression. The interaction between BCS status and years since diagnosis (< 5; ≥ 5) was tested in these models before and after covariate adjustment.

There were no overall sleep differences between BCS and controls; both groups experienced poor sleep health on average across multiple dimensions. Physical inactivity, sleep apnea, and vasomotor and depressive symptoms were associated with worse sleep in both groups. Total sleep time was lower among BCS than controls within 5 years of diagnosis (6.13 vs. 6.57 h; p = .03) but did not differ at > 5 years post-diagnosis (6.59 vs. 6.45 h; p = .32). BCS reported greater use of exogenous hormones (p < .0001) and were twice as likely to have initiated anxiolytic use post-diagnosis (p = .03).

BCS within 5 years of diagnosis experienced shorter sleep duration than controls but did not differ on other sleep parameters. Both groups experienced poor sleep health.

BCS and similarly-aged women experience poor sleep health requiring assessment and treatment.