Who is at risk for having persistent insomnia symptoms? A longitudinal study in the general population in Korea.
OBJECTIVE
Our study had three goals: (1) to investigate the longitudinal course of insomnia symptoms over 4 years (3 time points) by analyzing the trajectory of insomnia symptoms for all participants, (2) to compare persistent insomnia symptom to nonpersistent insomnia symptom groups on mental health and quality of life (QoL), and (3) to conduct exploratory analyses on the relative contribution of multiple factors to persistence of insomnia symptoms.


METHODS
Our population-based longitudinal study utilized a community-based sample from the Korean Genome and Epidemiology study (KoGES). Participants were 1247 individuals (40.1% men; mean age, 54.3±7.1 years). Insomnia, QoL (measured by 12-item Short-Form health survey [SF-12]), sleep-interfering behaviors, and depression (measured by the Beck Depression Inventory [BDI]) were followed with biennial examinations at 3 data points spaced 2 years apart (baseline, time 1, and time 2).


RESULTS
Among individuals experiencing insomnia symptoms at baseline, the most common trajectory was to experience persistent nocturnal insomnia symptoms across all 3 time points. Those with persistent insomnia symptoms had significantly lower physical and mental QoL (measured by SF-12) and higher depression (measured by BDI) at time points compared to those without persistent nocturnal insomnia symptoms. A follow-up exploratory receiver operating characteristic curve (ROC) analysis identified poor sleep quality, frequent sleep-interfering behaviors, and low mental health QoL as the strongest predictors of persistent insomnia symptoms above other well-known risk factors.


CONCLUSIONS
In particular, an interaction between poor sleep quality, sleep-interfering behaviors, and mental health QoL appeared to be the strongest risk factor for persistent insomnia symptoms.
Korea University Ansan Hospital, Institute of Human Genomic Study, Ansan, Republic of Korea; Stanford University, Department of Psychiatry, Palo Alto, CA, United States.
Sooyeon
S
Suh
Korea University Ansan Hospital, Institute of Human Genomic Study, Ansan, Republic of Korea; Yongmoon Graduate School of Counseling Psychology, Seoul, Republic of Korea.
Hae-Chung
HC
Yang
Stanford University, Department of Psychiatry, Palo Alto, CA, United States.
Christopher P
CP
Fairholme
Korea University Ansan Hospital, Institute of Human Genomic Study, Ansan, Republic of Korea; Department of Psychology, Boston University, Boston, MA, United States.
Hyun
H
Kim
Stanford University, Department of Psychiatry, Palo Alto, CA, United States. Electronic address: rmanber@stanford.edu.
Rachel
R
Manber
Korea University Ansan Hospital, Institute of Human Genomic Study, Ansan, Republic of Korea; Division of Pulmonary, Sleep and Critical Care Medicine, Department of Internal Medicine, Korea University Ansan Hospital, Ansan, Republic of Korea. Electronic address: chol-shin@korea.ac.kr.
Chol
C
Shin
D000368:Aged; D003863:Depression / Q000150:complications / Q000453:epidemiology; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008603:Mental Health / Q000706:statistics & numerical data; D008875:Middle Aged; D011569:Psychiatric Status Rating Scales; D011788:Quality of Life / Q000523:psychology; D012372:ROC Curve; D056910:Republic of Korea / Q000453:epidemiology; D012307:Risk Factors; D007319:Sleep Initiation and Maintenance Disorders / Q000453:epidemiology* / Q000209:etiology
Epidemiology; Insomnia; Longitudinal; Mental health; Quality of life; Sleep