Comparison of three measures for insomnia in ischemic stroke patients: Pittsburgh sleep quality index, insomnia severity index, and Athens insomnia scale

 So you described a way to quantify a problem, BUT DID NOTHING TO SOLVE IT! I fire all of you.

Comparison of three measures for insomnia in ischemic stroke patients: Pittsburgh sleep quality index, insomnia severity index, and Athens insomnia scale

Shuzhen Niu¹ Qian Wu¹ Silian Ding² Lingchun Wu³ Li Wang¹ Yan Shi^1*

• ¹Shanghai Tenth People's Hospital, School of Medicine, Tongji University, Shanghai, China
• ²Shanghai Fourth People's Hospital, Shanghai, China
• ³Department of Nephrology, Shanghai Zhabei Central Hospital, Shanghai, China

Objective: This study investigated the consistency and determined the optimal threshold values of three scales in the diagnosis of insomnia of ischemic stroke (IS) patients.

Methods: Participants in this study consisted of 569 acute IS patients. All 569 patients completed the assessment of the three insomnia scales. Insomnia of IS patients were assessed by Pittsburgh sleep quality index (PSQI), Insomnia Severity Index (ISI), and Athens insomnia scale (AIS). Also, basic patient information, neurological function, and activities of daily living were assessed. General information was compared between the insomnia group and the no-insomnia group. Cronbach’s α coefficients, Cohen’s Kappa consistency, Receiver operating characteristic (ROC) curve and DeLong’s test analysis were used to analyze the reliability and diagnostic validity of PSQI, ISI, and AIS.

Results: The PSQI and ISI showed high reliability with Cronbach’s α of 0.875 and 0.858, respectively, while the AIS had an α coefficient of 0.734, demonstrating acceptable reliability. The PSQI, ISI, and AIS showed outstanding diagnostic ability with an AUC of 0.960 (95% CI: 0.946, 0.974), 0.911 (95% CI: 0.882, 0.941), and 0.876 (95% CI:0.837, 0.916). The best diagnostic cutoffs for PSQI, ISI, and AIS are ≥9, ≥15, and ≥8.

Conclusion: Each of the three questionnaires has advantages and disadvantages when assessing insomnia. In the evaluation of insomnia in IS patients, the best questionnaire selection should be made according to the purpose of clinical evaluation and considering the sensitivity and specificity.

1. Introduction

Stroke is a leading cause of death and disability around the world (1). Ischemic stroke (IS) has high rates of morbidity, disability, recurrence and mortality (2). Insomnia is one of the common complaints of IS survivors. In contrast to other long-term sequelae of IS such as mobility and cognitive impairment, insomnia has received less attention and related research, despite being a risk factor for stroke (3). In accordance with the latest manual by the American Association of Sleep Medicine (AASM), insomnia is defined as persistent sleep problems and daytime socio-occupational dysfunction, which may be actual or perceived despite adequate sleep opportunities (4). According to the International classification of sleep disorders-3 edition (DSM-3) and the Chinese expert consensus on the assessment and management of stroke related sleep disorders (CEC-SSD) (5), stroke-related insomnia consists of two conditions: (i) post-stroke insomnia: insomnia first appears after stroke; (ii) stroke with insomnia: insomnia existing before stroke persists or worsens after stroke and meets the diagnostic criteria for insomnia. According to reports published 30 ~ 68% of poststroke patients were burdened with insomnia (6–8). In addition, insomnia is also thought to increase the risk of psychological problems (depression and anxiety), physical function (disability), and cognitive function (dementia) in IS patients (9, 10).

Strokes are more likely to occur in people who suffer from insomnia. The results of a meta-analysis of 160,867 patients in 15 studies showed that falling/maintaining asleep difficulty, and non-restorative sleep were positively strongly associated with the risk of stroke (11). According to a prospective clinical cohort study of stroke patients, insomnia patients were more likely to be depressed, anxious, disabled, and have difficulty returning to work than stroke patients without insomnia after 1 year after stroke (12). Surveys such as that conducted by Huang et al. (13) have shown that a negatively association between insomnia and the improvement in activities of daily living was found in subacute stroke inpatients. Tang et al. (14) showed that insomnia may make stroke survivors more susceptible to suicide. Kim et al. (10) demonstrated that insomnia had a negative effect on quality of life in stroke patients at the initial phases of rehabilitation. Also, insomnia IS patients have a higher recurrence stroke rate in the first year and a higher mortality rate within 6 years compared with no-insomnia IS patients (15).

Although the prevalence of insomnia continues to rise in many countries around the world (16, 17), patients often treat insomnia as a lifestyle issue rather than a major health problem (18). Also, the importance of insomnia diagnosis has been neglected in the routine medical examination of some IS patients. Clinician assessment and judgment based on the DSM-5 and CEC-SSD remain the criteria for diagnosing insomnia in stroke patients. Polysomnography (PSG) is considered as a common objective measure for the measurement of sleep disorders. However, PSG is not easy to obtain for most clinicians’ daily insomnia diagnosis routine (19), and is mostly used for the diagnosis of sleep disordered breathing (SDB). At the same time, PSG is very expensive for epidemiology and research, takes a long time and is not in line with clinical practice (19). However, multiple insomnia questionnaires have been developed including the PSQI, ISI, and AIS. All three questionnaires were used multiple times and translated into multiple languages and have been widely used in China. These questionnaires are considered to be efficient screening tools for insomnia. They are simple to perform and cost effective and do not demand additional special apparatus or facilities. The use of brief questionnaires for subjective assessment saves time and effort and ensures a high level of patient subjective willingness and compliance. Also, due to the self-explanatory nature of these tools, the need for and reliance on specialists and clinicians can be significantly reduced (20, 21). The three insomnia assessment tools used in this study, PSQI, ISI, and AIS, were not developed specifically for IS patients, and each scale validation was based on primary sleep disorders patients (22). Because of the significant role that the rating scales plays in the diagnosis of insomnia in IS patients, psychometric properties, cut-off values and diagnosis effectiveness of these tools need to be evaluated in IS patients. The purpose of this study was to the establish reliability and determine the optimal threshold values of PSQI, ISI, and AIS in the diagnosis of insomnia of IS patients.