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. 2018 Jul 27;8:11375. doi: 10.1038/s41598-018-29747-2

Table 4.

Association between UNGD and disordered sleep in a weighted generalized estimating equations model (n = 3,658a).

UNGD groupb Disordered sleep diagnosisc
OR (95% CI)
Very low 1.00
Low 0.96 (0.73–1.25)
Medium 1.06 (0.80–1.40)
High 1.06 (0.79–1.42)

Abbreviations: CI = confidence interval; OR = odds ratio; UNGD = unconventional natural gas development.

aIncludes 1699 cases and frequency-matched controls. Excludes follow-up responders outside of Pennsylvania (n = 34) and those that answered no depression symptom questions (n = 170).

bThe UNGD metric was a composite for four phases of well development (pad preparation, drilling, stimulation, and production) and was assigned for the three months prior to each event.

cModels included truncated survey weights and adjusted for race/ethnicity (White non-Hispanic, Black non-Hispanic, Hispanic), sex (male, female), Medical Assistance (no, yes), age (years, linear and quadratic terms), smoking status (never, former, current), alcohol status (no; yes, not heavy; yes, heavy), body mass index (BMI, kg/m2, linear and quadratic terms), community socioeconomic deprivation (linear and quadratic terms), and water source (municipal water, well water).