**3. Results**

A total of 1229 articles were screened for eligibility (**Figure 1**). Of the 1229,80 initially met inclusion criteria. Forty-nine were subsequently excluded. A total of 31 studies were selected for review. The majority of studies with self-report or polysomnographic data reported no significant differences in age or gender ratio

**101**

**Table 2.**

*A Meta-Analysis of Sleep Disturbances in Panic Disorder DOI: http://dx.doi.org/10.5772/intechopen.86306*

size, average control group size was 46 participants.

**95% CI Standard error**

recruited through local media.

**3.1 Self-report sleep data**

duration scales.

PSQI subjective sleep quality

PSQI sleep latency

PSQI sleep duration

PSQI sleep efficiency

PSQI sleep disturbances

PSQI daily dysfunction

PSQI global score

*CI = confidence interval.*

**Variable Effect size** 

**(Hedges' g)**

1.76\* [1.26,

1.31\* [0.42, 2.21]

−0.18 [−1.33, 0.98]

0.81 [−0.08, 1.70]

1.56\* [0.65,

1.71\* [1.38,

1.31\* [0.53,

*\*= Significant differences between groups, p < 0.05.*

*\*\*= Significant heterogeneity, p < 0.05.*

*Meta-analysis results for self-report data.*

2.47]

2.04]

2.08]

*Note: PSQI = Pittsburgh sleep quality index; — = insufficient number of studies to report heterogeneity;* 

2.31]

between PD and control groups. Of the 31 studies analyzed, seven included participants taking medication. Participants were medication-free in all but one of the polysomnographic studies. In all studies, PD diagnoses were made using validated diagnostic interviews. The majority of patient samples were recruited in clinics/ hospitals or were referred by a health professional. Control participants were mostly

Of the 31 selected articles, seven reported self-report data. All seven studies used the PSQI. The component scales of subjective sleep quality, sleep latency, sleep duration, sleep efficiency, sleep disturbances, daytime dysfunction, and the PSQI global score were analyzed. The sixth PSQI scale (medication use) was not analyzed because the variable was outside the scope of the present study. Pooled PD group size ranged from 47 to 182 participants (average = 94 participants). Pooled control groups ranged from 15,151 to 15,238 participants (average = 15,163 participants) (**Table 2**). The wide difference between average group size in PD and control groups was due to the presence of one study whose control group was 15,117 participants. When this study was removed from calculations of the average sample

Analyses revealed that patients with PD had significantly greater scores than healthy controls for the PSQI scales of sleep quality, sleep latency, sleep disturbances, daily dysfunction, and global score. This means that patients with PD reported worse sleep quality, longer sleep latency, more sleep disturbances, and more daily dysfunction. All effect sizes were large as per Cohen's criteria [44]. There were no significant differences between groups on PSQI sleep efficiency and sleep

**Variance Q I**

**<sup>2</sup> Number of studies**

0.28 0.08 — — 2 89 15,151

0.46 0.21 — — 2 89 15,151

0.59 0.35 — — 2 89 15,151

0.45 0.21 — — 2 89 15,151

0.46 0.22 — — 2 89 15,151

0.17 0.03 — — 2 89 15,151

0.40 0.16 69.38\*\* 92.79 6 182 15,238

**PD group sample size**

**Control group sample size**

**Figure 1.** *Study selection flow chart.*

between PD and control groups. Of the 31 studies analyzed, seven included participants taking medication. Participants were medication-free in all but one of the polysomnographic studies. In all studies, PD diagnoses were made using validated diagnostic interviews. The majority of patient samples were recruited in clinics/ hospitals or were referred by a health professional. Control participants were mostly recruited through local media.
