Erratum

In Buysse DJ; Hall ML; Strollo PJ; Kamarck TW; Owens J; Lee L; Reis E; Matthews KA. Relationships between the Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS), and clinical/ polysomnographic measures in a community sample. J Clin Sleep Med 2008;4(6):563–571 an error was identified by the authors during subsequent analyses of their data set. The error is in the reported scores on the Center for Epidemiological Studies-Depression Scale (CES-D). The authors state that this error affects one reported statistical test value, but it does not change any of the major findings or conclusions of the paper.

The error affects the following portions of the manuscript:

1. Table 2, line 13

   		Cluster 1	Cluster 2	Cluster 3	Cluster 4	Statistical Results
   Current data	Center for Epidemiological Studies Depression (less sleep item)	9.3 (9.2)	9.6 (10.0)	9.2 (9.3)	12.6 (9.5)	n.s.
   Correct data	Center for Epidemiological Studies Depression (less sleep item)	4.3 (5.9)a	5.5 (5.3)a	5.3 (6.7)a	9.3 (7.7)b	0.02

2. Text describing Table 2, page 567, 1st column, 2nd paragraph:

   Current text–“the groups differed on 5/10 clinical self-report measures...”

   Correct text–“the groups differed on 6/10 clinical self-report measures...#x201D;

3. Text page 567, 2nd column, 1st paragraph:

   Current text–“Significant differences among groups were found for self-report psychological symptom measures (Ford Insomnia Response to Stress Test, Perceived Stress Scale, Spielberger Anxiety Scale...”

   Correct text–“Significant differences among groups were found for self-report psychological symptom measures (Ford Insomnia Response to Stress Test, Perceived Stress Scale, Center for Epidemiological Studies Depression Scale, Spielberger Anxiety Scale...”

4. Text page 567, 2nd column, 2nd paragraph, last sentence on page:

   Current text–“PSQI scores were significantly related (p > 0.004) to all self-report symptom measures except ongoing stress, depression, and unfair treatment...”

   Correct text–“PSQI scores were significantly related (p > 0.004) to all self-report symptom measures except ongoing stress, and unfair treatment...”

The authors regret this error.