| Gmez-Benito et al., 2011 [45]: AIS-8 and AIS-5 | A total of 323 individuals (227 females); mean age of 30.29 years: 167 students (138 females; mean age of 20.50 years), 77 psychiatric outpatients (38 females; mean age of 40.16 years) and 79 community sample (56 females; mean age of 43.42 years) | AIS-8: 1-factor model (51.50% of variance explained) and factor loading ranging from 0.488 to 0.858.AIS-5: 1-factor model (54.33% of variance explained) and factor loading ranging from 0.614 to 0.818 | Cronbachs alpha for AIS-8 was 0.86. Cronbachs alpha for AIS-5 was 0.79.For AIS-8 Cronbachs alphas for undergraduates, patients and the general population were 0.81, 0.89, and 0.86, respectively.For AIS-5 Cronbachs alpha for undergraduates, patients and the general population were 0.66, 0.83, and 0.78, respectively | A 1-month test-retest for AIS-8 (ICC = 0.75) and for AIS-5 (ICC = 0.64) | AIS-8 and AIS-5 correlated with BDI (0.53 and 0.46, respectively), with BAI (0.49 and 0.42 respectively) and with GHQ-12 (0.54 and 0.44 respectively) | For AIS-8: students (4.83) < community sample (6.20) < psychiatric patients (8.12).For AIS-5: students (2.82) < community sample (4.22) or psychiatric patients (5.22) | Spanish |
| Okajima et al., 2013 [48]: AIS-J | A total of 640 individuals (371 females); mean age of 48.8 years: 477 outpatients with chronic insomnia (253 women; mean age of 47.9 years) and 163 individuals who scored less than 6 points on PSQI-J (54 women; mean age of 51.3 years) | A 2-factor structure: Nocturnal Sleep Problems (AIS-J-nocturnal, items 15; factor loading 0.330.87) and Daytime Dysfunction (AIS-J-daytime, items 68; factor loading 0.450.94).Inter-factor correlation was 0.62 | Cronbachs alpha for total score was 0.88 and for F1 and F2 it was 0.85 and 0.78, respectively | There was a correlation between AIS-J and PSQI-J (0.81) and between AIS-J and ISI-J (0.85).In patients with insomnia there were correlations between AIS-J and PSQI-J (0.57) and between AIS-J and ISI-J (0.58) but no significant correlations were found in patients with depression or those with anxiety disorder (rs n.a.) | Insomnia group with higher scores than control group for AIS-J (11.81 vs. 2.64), Nocturnal (8.12 vs. 1.63) and Daytime (3.65 vs. 1.01) factors. Insomnia, depression and anxiety disorder groups (above 11) > healthy controls (less than 3). Same results for Nocturnal factor (above 6 for patients and below 2 for controls). For Daytime factors, depression and anxiety disorder groups (above 4) had higher scores than primary insomnia (about 3) and controls (about 1) | AIS-J: ROC curve for insomnia (primary and secondary) with AUC = 0.96 for cut-off of 5.5 and sensitivity = 92% and specificity = 93% (LR+ = 13.62 and LR = 0.09.AIS-J-nocturnal: ROC curve for insomnia (primary and secondary) with AUC = 0.97 for cut-off of 3.5 and sensitivity = 93% and specificity = 94% (LR+ = 16.73 and LR = 0.07).For primary insomnia AIS-J > 5.5 with AUC = 0.97, sensitivity = 93%, specificity = 93%, LR+ = 13.78, LR = 0.08; AIS-Jnocturnal > 3.5 with AUC = 0.97, sensitivity = 94%, specificity = 94%, LR+ = 16.88, LR = 0.07 | Japanese |
| Jeong et al., 2015 [46]: AIS-8 | A total of 221 firefighters and rescue workers (14 women); mean age of 40.3 years | A 1-factor structure (95.73% of variance explained) with factor loading of each item ranging from 0.51 to 0.82 | Cronbachs alpha of 0.88. Mean item-total correlation coefficient was 0.73 (0.560.84 range) | A 1 week test-retest with ICC for total score equal to 0.94 (0.580.95 range) | AIS-8 correlated with PSQI (0.82), ISI (0.85), ESS (0.29), SF-36 mental component summary (0.53), SF-36 physical component summary (0.37), but not with AUDIT-C (0.10) or socioeconomic status (0.01) | Based on Structured Clinical Interview for the DSM-IV-TR and a structured clinical interview for insomnia, participants were divided into non-insomnia, participants with insomnia symptoms (group 1), individuals with disturbed daily functioning (group 2) and those in group 2 who had symptoms even during off-duty periods.Non-insomnia group (4.1) < group 1 (9.3) < group 2 (10.1) | ROC curve for group 1 with cut-off score AIS-8 = 6, AUC = 0.87, sensitivity = 87%, specificity = 72%, LR+ = 3.07, LR = 0.18;ROC curve for group 2 with cut-off score AIS-8 = 8, AUC = 0.84, sensitivity = 73%, specificity = 79%, LR+ = 3.50, LR = 0.35; ROC curve for group 3 with cut-off score AIS-8 = 9, AUC = 0.85, sensitivity = 71%, specificity = 84%, LR+ = 4.45, LR = 0.34 | Korean |
| Enomoto et al., 2018 [49]: AIS-8 and AIS-5 | A total of 144 outpatients with a history of pain (86 females); mean age of 53.3 years | AIS-8: 2-factor model without item 8 with poor factor loading: Nocturnal Sleep Problem (items 15) and Daytime Dysfunction (67).AIS-5: 1-factor (Nocturnal Sleep Problem) model with a covariation between item 1 and item 5 (0.30) and factor loading > 0.60 | Cronbachs alpha for AIS-8 was 0.87 and for AIS-5 was 0.89.For nocturnal sleep problems the Cronbachs alpha was 0.89 and for daytime dysfunction was 0.66 | An 87.4 day test-retest with overall ICC of 0.64 for AIS-8, 0.72 for the AIS-5 and nocturnal sleep problems and 0.54 for daytime dysfunction | AIS-8 correlated with NRS (0.36), PDAS (0.46), HADS-anxiety (0.54), HADS-depression (0.64), PCS-total (0.36), PCS-rumination (0.23), PCS-magnification (0.37), PCS-helplessness (0.35), PSEQ (0.47).AIS-5 correlated with NRS (0.35), PDAS (0.37), HADS-anxiety (0.42), HADS-depression (0.52), PCS-total (0.26), PCS-rumination (0.17), PCS-magnification (0.27), PCS-helplessness (0.24), PSEQ (0.35) | Based on the semi-structured interview data, participants were divided into an insomnia group and non-insomnia group.Insomnia group (AIS-8 = 11.4; AIS-5 = 7.1) > non-insomnia group (AIS-8 = 5.2; AIS-5 = 2.7) | ROC curve to detect insomnia with AIS-8 = 8, AUC = 0.82, sensitivity = 72%, specificity = 85%.ROC curve to detect insomnia with AIS-5 = 4, AUC = 0.82, sensitivity = 78%, specificity = 70% | Japanese |
| Iwasa et al., 2018 [50]: AIS-SJ | A total of 50,547 community dwellers who lived in the evacuation zone designated by the government for Fukushima Dalichi NPP Incident (27.669 women); mean age of 52.9 years | A 2-factor model:F1 or Nocturnal (items 15; factor loading from 0.71 to 0.87) and F2 or Daytime (items 68; factor loading from 0.62 to 0.91). Inter-factor correlation was 0.77 | Cronbachs alpha for all 8 items was 0.81. Cronbachs alpha for F1 was 0.80 and for F2 was 0.76 | Correlations appeared between total AIS-SJ score and K6 scale (0.60), PCL-S (0.60), mental illness (0.36), self-rated health (0.51), experiencing tsunami (0.10), experiencing NPP incident (0.18), bereavement (0.17), housing damage (0.13) and losing job (0.15). There was the same correlation pattern for F1 (0.100.54 range) and for F2 (0.080.56 range) | Young men (2.76) had similar AIS-SJ score to that of old men (2.82). Older women (3.49) had higher AIS-SJ score than young women (3.19). Women (3.27) had higher AIS-SJ score than men (2.80).Older adults (2.06) had higher Nocturnal score than younger adults (1.86). Women (2.12) had higher Nocturnal score than men (1.80). Younger adults (1.12) had higher Daytime score than older adults (1.09). Women (1.21) had higher Daytime score than men (1.00) | Japanese |
| Lin et al., 2020 [47]: AIS-8 and ISI | A total of 573 patients with cancer at stage III or IV (247 females); mean age of 61.3 years | AIS-8: 1-factor structure (adequate average variance extracted = 0.56) with factor loadings from 0.61 to 0.87 and Rasch-derived infit (0.81 to 1.17) and outfit (0.79 to 1.14) mean square fitted the underlying construct; no substantial DIF was found across the sex (DIF contrast = 0.43 to 0.43) or insomnia condition (DIF contrast = 0.23 to 0.19).ISI: 1-factor model (adequate average variance extracted = 0.54) with factor loadings from 0.61 to 0.81 and Rasch-derived infit (0.72 to 1.14) and outfit (0.76 to 1.11) mean square fitted the underlying construct; no substantial DIF was found across the sex (DIF contrast = 0.12 to 0.48) or insomnia condition (DIF contrast = 0.19 to 0.33) | AIS-8: satisfactory internal consistency ( = 0.88), high composite reliability (0.91), low standard error of measurement (2.57), corrected item-total correlations from 0.56 to 0.76, separation reliability (0.88 and 0.84) and separation indices (2.75 and 2.30) were acceptable.ISI: satisfactory internal consistency ( = 0.79), high composite reliability (0.89), low standard error of measurement (2.00), corrected item-total correlations from 0.43 to 0.67, separation reliability (0.98 and 0.78) and separation indices (7.20 and 2.71) were acceptable | A 2-week test-retest reliability for AIS-8 was satisfactory (0.72 to 0.82) and ICC = 0.82.2-week test-retest reliability for ISI was satisfactory (0.72 to 0.82) and ICC = 0.79 | AIS-8 and ISI were mutually correlated (0.64).AIS-8 was correlated with ESAS (0.38), HADS-anxiety (0.58), HADS-depression (0.56), KPSS (0.50), GHQ-12 (0.61), ESS (0.62) and PSQI (0.55).ISI correlated with ESAS (0.41), HADS-anxiety (0.53), HADS-depression (0.62), KPSS (0.41), GHQ-12 (0.54), ESS (0.64), and PSQI (0.58) | AIS-8 and ISI: patients who took opioids had the highest AIS scores (9.48 and 10.33) followed by those taking non-opioid analgesics (7.13 and 7.60) and those taking other medications (7.29 and 6.41).AIS < 7 (insomniacs) vs. AIS > 7 (non-insomniacs): difference for actigraph data of TST, SE, bedtime, wake time, SOL, and WASO.ISI < 9 (insomniacs) vs. ISI > 9 (non insomniacs): difference for actigraph data of TST, SE, bedtime, wake time, SOL, and WASO | ROC curve with cut-off score of AIS-8 = 7 for detecting insomnia with AUC = 0.86, sensitivity = 86% and specificity = 81%.ROC curve with cut-off score of ISI = 9 for detecting insomnia with AUC = 0.82, sensitivity = 86% and specificity = 83%.AIS-8 and ISI cut-offs were consistent with psychiatric diagnosis based on DSM-IV | Persian |
| Yu, 2010 [58]: ISI-C | A total of 585 Chinese community-dwelling older people (474 females); mean age of 74.3 years | A 2-factor model (61.40% of the total variance) with factor loadings ranging from 0.56 to 0.85: F1 (items 14) assessing severity of sleeping difficulties; F2 (items 57) assessing daytime interference and distress associated with insomnia as well as how noticeable the sleeping problem was | Cronbachs alpha of 0.81. Corrected item-to-total correlation for the items was in the range of 0.330.67.Cronbachs alpha for F1 = 0.788. Cronbachs alpha for F2 = 0.640 | ISI-C correlated with CPSQI (0.686) and with sleep efficiency derived from CPSQI item scores (0.583) | Depressed adults reported by GDS had higher scores on the ISI-C (12.61) than those without this problem (9.19).Poorer sleepers defined by the CPSQI cut-off point 5 had a higher ISI-C score than those of normal sleepers [mean not reported] | Chinese |
| Fernandez-Mendoza et al., 2012 [62]: ISI | A total of 500 adults from the general population (307 females); mean age of 39.13 years | A 3-factor model with Impact of Insomnia (items 57), Sleep Dissatisfaction (items 1, 4, 7) and Night-time Sleep Difficulties (items 13).Mean inter-item correlations were 0.35 (night-time sleep difficulties), 0.59 (impact of insomnia) and 0.50 (sleep dissatisfaction).Inter-factor correlations were found between Impact of Insomnia and Sleep Dissatisfaction (0.61), between Sleep Dissatisfaction and Night-time Sleep Difficulties (0.83) and between Impact of Insomnia and Night-time Sleep Difficulties (0.48) | Cronbachs alpha was 0.82.Cronbachs alpha of factors was 0.60 (for night-time sleep difficulties), 0.81 (for impact of insomnia) and 0.75 (for sleep dissatisfaction).Corrected item-to-total correlation for the items ranged from 0.47 to 0.71 | ISI correlated with PSQI (0.68), ESS (0.18), POMS-fatigue (0.40), POMS-depression (0.34) and POMS-anxiety (0.38).Impact of insomnia correlated with PSQI (0.49), ESS (0.26), POMS-fatigue (0.45), POMS-depression (0.38) and POMS-anxiety (0.41).Sleep dissatisfaction correlated with PSQI (0.68), ESS (0.11), POMS-fatigue (0.34), POMS-depression (0.27) and POMS-anxiety (0.33).Sleep difficulties correlated with PSQI (0.62), POMS-fatigue (0.23), POMS-depression (0.22) and POMS-anxiety (0.23), but not ESS (0.04) | 85% of subjects classified as insomniacs in the ISI total score 8 were classified as poor sleepers in the PSQI total score > 5 and 33% of non-insomniacs were classified as poor sleepers | Spanish |
| Sadeghniiat-Haghighi et al., 2014 [59]: ISI-P | A total of 1037 patients referred to a sleep disorder clinic (301 females; mean age of 45.4 years) and 50 hospital staff (31 females; mean age of 32.1 years) | A 2-factor model (60.58% of variance observed):F1: item 1a, item 1b, item 1c and item 2 (factor loading ranged from 0.57 to 0.77);F2: items 35 (factor loading ranged from 0.64 to 0.83) | Cronbachs alpha in patients was 0.78.Corrected item-total correlations ranged from 0.35 to 0.63 | ISI-P correlated with ESS (0.12), BDI (0.42) and PSQI (0.74)ISI total score correlated with PSG variables such as WASO (0.12) and SE (0.13). Item 1a correlated with WASO (0.17), EMA (0.14), TST (0.22), TWT (0.19) and SE (0.24). Item 1b correlated with WASO (0.12), TST (0.12) and SE (0.14). Item 1c correlated with SOL (0.12), WAS (0.12), EMA (0.17), and SE (0.10). Item 2 correlated with SE (0.10).Item 1a correlated with C2-PSQI (0.61), item 1b correlated with C5-PSQI (0.18), item 1c correlated with C5-PSQI (0.13), item 2 correlated with C1-PSQI (0.41), and item 3 correlated with C7-PSQI (0.43) | Patient group (15.90) > control group (10.10) | Persian |
| Dragioti et al., 2015 [54]: ISI-4 | A total of 836 patients with chronic pain (269 men with mean age of 50 years and 567 women with mean age of 45 years) | And 1-factor model (63.1% of variance explained) with factor loadings ranging from 0.598 to 0.880.In 109 men the 1-factor solution was confirmed (66.8% of variance explained with factor loadings from 0.591 to 0.905).In 225 women the 1-factor solution was confirmed (62.4% of variance explained with factor loadings from 0.597 to 0.880). In 502 patients the 1-factor solution was found with only 4 items (items 2, 4, 5 and 7: factor loadings from 0.72 to 0.88) and no sex difference was found | Cronbachs alpha of ISI-4 was 0.88.Component-to-total score correlations were high (0.650.80).Inter-component analysis revealed correlations between items from 0.53 to 0.75 | ISI-4 correlated with HADS-anxiety (0.37), HADS-depression (0.35), quality of sleep (0.65) and mental dimension of quality of life (0.35).No correlation with age (p > 0.05) | No gender difference (men = 10.22 vs. women = 9.80).Multiple linear regression analysis showed that both sex and pain duration affected the score of the ISI-4 whereas pain intensity was associated with the ISI-4 score | Swedish |
| Castronovo et al., 2016 [63]: ISI | A total of 272 consecutive patients (165 females) with insomnia diagnosis and enrolled in a CBT-I; mean age of 41.36 years | A 3-factor model with Impact (items 35), Satisfaction (items 1a, 2, 5) and Severity (items 1a, 1b, 1c).There were inter-factor correlations between Impact and Satisfaction (0.45), between Impact and Severity (0.25) and between Satisfaction and Severity (0.76). Factor loadings in absolute value ranged from 0.33 to 0.99 | Ordinal alpha was 0.75 with an increase to 0.76 with the first item removed.The corrected item-to-total correlation for the items ranged from 0.49 to 0.74 | After CBI-I treatment the ordinal alpha was 0.73 | Correlations between the severity ratings obtained in the first three items of the ISI with corresponding quantitative estimates of SOL (0.44 ISI1a), WASO (0.33 ISI1b), NAWK (0.28 ISI1b), EMA (0.44 ISI 1c) obtained from the sleep diaries, the total ISI score and SE (0.28) variable from the sleep diary correlated with the Impact scale and SOL (0.14; but not with NAWK, WASO, EMA, SE), Satisfaction scale and SOL (0.36), WASO (0.19), EMA (0.19), SE (0.26; but not with NAWK) and between Severity scale and SOL (0.21), NAWK (0.20), WASO (0.32), EMA (0.45), SE (0.39) | Follow-up evaluations from baseline and follow-up after a CBT-I treatment: percentage of responses 3, 4, and 5 decreased, indicating a general improvement in patients conditions. Total score of the ISI and scores obtained in each scale were lower after CBT-I | Italian |
| Gerber et al., 2016 [55]: ISI | Study 2: 862 students (639 women) with mean age of 24.7 years.Study 3: 533 employees of the police force and emergency response service corps (122 women) with mean age of 41.2 years | Studies 2 and 3:1-factor solution for men and women with factor loadings from 0.11 to 0.90 (males) and from 0.11 to 0.89 (females).Item 5 with factor loadings of 0.31 and 0.29 for Study 2 and of 0.26 and 0.26 for Study 3.Item 6 with factor loadings of 0.11 and 0.11 for Study 2 and of 0.13 and 0.13 for Study 3 | Study 2: Cronbachs alpha was 0.77 in the total sample, 0.78 for men and 0.76 for women.Inter-item correlations were above the critical value of 0.20 (with the exclusion of item 6). Item-total correlations were found for men and women (with mean correlations of 0.51 for men and 0.49 for women)Study 3: Cronbachs alpha was 0.81 in the total sample, 0.81 for men and 0.82 for womenInter-item correlations exceeded the critical value of 0.20 (with few cases for item 6). Item-total correlations were on average correlations of 0.55 for men and 0.56 for women | Study 2: for males correlations were found between total ISI scores and each item and PSQI with 0.140.55 range with few exceptions (below 0.10). Total ISI correlated with all sleep variables of PSQI (range 0.19 and 0.54) with the exception of sleep duration. There were correlations between all items and total scores (0.310.50 range; but not item 6) with Depression scale.The same pattern appeared for females (0.130.69). ISI correlated with the Depression scale (0.190.51 range).Study 3: for males there were correlations between ISI and each item with PSQI (0.110.69 range with few exception with r < 0.10). ISI and each item correlated with SF-12 (from 0.20 to 0.46). The same pattern was evident in females with PSQI (0.180.75 range) and with SF-12 (from 0.22 to 0.45 with the exception of item 6) | Study 2: women (6.80) > men (5.91) for total ISI score. There were also gender differences for item 1 and item 2 but not for the other items.Study 3: no gender difference was evident for the total ISI score (women: 7.00 and men: 6.97) and there were no differences for any item | Cut-off:07 no clinically significant insomnia,814 sub-threshold insomnia,1521 clinical insomnia (moderate severity)2228 clinical insomnia (severe) | German |
| Dieck et al., 2018 [56]: ISI | A total of 700 participants (573 females); mean age of 32.16 years | A 3-factor model:F1 (items 2, 4, 7), F2 (items 1), F3 (items 57). Item 3 was not assigned to one factor. Correlations between F1 and F3 (0.744), but not for F1 and F2 (0.209) or between F2 and F3 (0.180).1-factor model estimated with the quartimin rotation method and weighted least squares method: factor loadings from 0.409 (item 3) to 0.901 (item 7) | Cronbachs alpha of the ISI was 0.83 and the item-total correlation ranged from 0.36 to 0.77 | A 2-week test-retest for total score of the ISI was 0.77, and the individual items ranged from 0.51 to 0.73 with only item 3 (0.54) and item 6 (0.51 showed weak test-retest.Test-retest with PSQI 5 (0.310.58) and PSQI > 5 (0.420.78). Test-retest with PSQI > 5 and BDI-II < 20 (0.350.74) | Correlations between ISI and PSQI (0.79, 0.61, 0.77), between ISI and BDI-II including sleep item (0.55, 0.37, 0.66), between ISI and BDI-II excluding sleep item (0.56, 0.36, 0.64) and between ISI and SRS (0.36) | Based on PSQI value 5 ROC curve with cut-off ISI > 10 with AUC = 0.94, sensitivity = 91% and specificity = 84% (LR+ = 5.86; LR = 0.10). Based on BDI-II < 20 ROC curve with cut-off score ISI > 10 with sensitivity = 87.28%, specificity = 84.72% (LR+ = 5.71, LR = 0.15) | German |
| Kaufmann et al., 2019 [57]: ISI | A total of 83 Operation Enduring Freedom/Operation Iraqi Freedom/Operation New Dawn veterans with a history of TBI (11 females); mean age of 32.5 years | 1-factor model (69.0% of variance explained) with total eigenvalues = 4.83 and factor loadings > 0.70 | Cronbachs alpha was 0.92 | ISI total score was correlated with NSI (0.76) and BDI-II (0.56) sleep item, the PSQI global score (0.76) and with the ESS total score (0.32).The ISI was correlated with the PSQI individual component score (ranging from 0.324 to 0.791, with the exclusion of C6 with 0.226).ISI total score correlated with BAI (0.450), PCL-M total with sleep item excluded (0.513) and BDI-II with sleep item excluded (0.476) | Categorical scores:07 as no insomnia814 as sub-threshold insomnia1521 as moderate insomnia2228 as severe insomnia.Cut-off of ISI > 11 with 67.5% were classified as having clinical insomnia.Based on PSQI cut-off score of > 8 to indicate elevated insomnia symptoms, ROC curve with AUC = 0.87, sensitivity = 81% and specificity = 71% with cut-off ISI > 11.5 | English(American) |
| Dieperink et al., 2020 [61]: ISI-DK | A total of 249 patients with a medical condition (158 females); mean age of 58.2 years | A 2-factor model with Severity factor (items 14; factor loadings from 0.57 to 0.88) and Impact factor (items 57; factor loadings from 0.73 to 0.90) and correlation between factors (0.88).3-factor model with Severity factor (items 13; factor loadings from 0.59 to 0.92), Impact factor (items 57; factor loadings from 0.72 to 1.30) and Dissatisfaction factor (items 1, 4, 7; factor loadings from 0.36 to 0.85) and inter-factor correlations between severity and dissatisfaction (0.94), between severity and impact (0.81) and between dissatisfaction and impact (0.95) | Cronbachs alpha was 0.90 with item-total correlation interval between 0.520.80 and a mean value of 0.71.When item 3 was deleted the Cronbachs alpha increased to 0.91.For the 2-factor model, the Cronbachs alpha of Severity factor was 0.83 and that of Impact factor was 0.88.For the 3-factor model the Cronbachs alpha of Severity factor was 0.75, that of Dissatisfaction factor was 0.81 and that of Impact factor was 0.88 | 17.1 days test-retest with ICC = 0.90, with SEM = 2.52, SDC = 6.99 and LoA = 0.05 | No gender difference (male = 9.36 vs. female = 10.74).Responders 70 years old (8.85) had lower ISI-DK scores compared to younger responders (10.65).Responders with EQ VAS score < 83.7 (11.21) had a higher ISI-DK score compared to responders with a higher EQ VAS score (7.18). Responders with anxiety/depression (12.50) had a higher IS-DK score compared to responders with no problem (8.23).Responders with pain/discomfort problems (11.21) had higher ISI-DK scores compared to responders with no problem (7.44) | Using the insomnia cut-offs 25.4% had moderate insomnia (1521) and 2.4% had severe insomnia (2228) | Danish |
| Manzar et al., 2020 [60]: ISI | A total of 406 substance-using community dwelling adults (54 females); mean age of 27 years | A 2-factor model with the incorporation of modification indices to covary the error terms (cumulative variance explained = 63.41%): F1 (items 13; factor loading from 0.67 to 0.76) and F2 (items 47; factor loading from 0.51 to 0.80). Inter-factor correlation was 0.52 | Cronbachs of F1 was 0.68 and of F2 was 0.78.The item-total correlations of the ISI were 0.470.72. Inter-item (homogeneity) correlations ranged from 0.11 to 0.57 with the exception of the correlation between item 1 and item 7 | All of the item scores of the ISI, both factor scores and the ISI total score, correlated with the meta-cognition total score (0.160.44 range) and its factor scores: meta-memory (0.190.35 range) and meta-concentrations (0.100.44 range) | Ethiopian |
| Natale et al., 2014 [66]: MSQ | A total of 1830 university students and their parents/grandparents (1073 women); mean age of 35.70 years | A 2-factor model (49.8% of variance explained): Wake dimension (items 4, 5, 8, 9; factor loadings from 0.52 to 0.83) and Sleep dimension (items 13, 7, 10; factor loadings from 0.51 to 0.75). Only item 6 (snoring) had a loading value of 0.39 and it was not loaded on any dimension.This 9-item solution was a better model in comparison to the 10-item solution | Cronbachs alpha for the MSQ was 0.77. The average inter-item correlation (homogeneity) was 0.26, ranging between 0.01 and 0.58.Cronbachs alpha of wake dimension was 0.75 and that of homogeneity 0.44.Cronbachs alpha of sleep dimension was 0.75 and homogeneity amounted to 0.37 | Based on SDQ, healthy participants obtained lower scores in the wake dimension (11.92) in comparison to participants compatible with EDS (17.27).Healthy participants obtained lower scores in the sleep dimension (12.48) in comparison to participants compatible with impaired sleep quality (18.75) | ROC curve with cut-off value for wake dimension > 14 with AUC = 0.83, sensitivity = 78%, specificity = 74%, PPV = 0.29 and NPV = 0.96.ROC curve with cut-off value for sleep dimension > 16 with AUC = 0.82, sensitivity = 73%, specificity = 80%, PPV = 0.40, and NPV = 0.94 | Italian |
| Kim, 2017 [67]: MSQ-Insomnia | A total of 470 students from six nursing colleges in South Korea (437 females); mean age of 21.40 years | A 1-factor model (56.0% of the variance explained): MSQ-Insomnia with 4 items (items 14) loading from 0.33 (item 3: taking sleeping pills and tranquilizers) to 0.89 (item 2: awakening early in the morning and unable to sleep again) | Cronbachs alpha of MSQ-Insomnia was 0.69. Item-total correlations ranged from 0.30 (item 3) to 0.68 (item 2).Cronbachs alpha increased to 0.73 if item 3 was deleted | Test-retest with ICC = 0.84.No difference in MSQ-Insomnia score between baseline and retest | MSQ-Insomnia correlated with PSQI (0.69), as well as each item of MSQ-Insomnia correlated with PSQI (item1: 0.71, item 2: 0.52, item 3: 0.22, item 4: 0.42).MSQ-Insomnia correlated with PSS (0.31) as well as each item of MSQ-Insomnia correlated with PSS (item 1: 0.26, item 2: 0.25, item 3: 0.11, item 4: 0.24) | Based on the PSQI cut-off score of 8.5, 98 students were classified as poor sleepers. The MSQ-Insomnia had a good level of predictive validity (AUC = 0.85) to predict poor sleepers | Korean |
| Tibubos et al., 2020 [69]: JSS-4 | A total of 2515 representative individuals of the German population (1350 females); mean age of 50.53 years | A 1-factor model (eigenvalue of 3.10) accounting for 77.5% of total variance. Factor loadings ranged between 0.83 and 0.93.1-factor solution confirmed with CFA (standardized factor loadings ranged between 0.71 and 0.95) | Cronbachs alpha of 0.90 and Mc Donalds omega of 0.90.Corrected item-total correlations ranged from 0.69 (item 4) to 0.86 (item 3) in total sample (range 0.670.86 in men and 0.700.86 in women) | Correlations were present between JSS-4 total and sex (0.10), age (0.28), household income (0.19), BSI-18 total score (0.51), BIS-18 anxiety (0.42), BSI-18 depression (0.41), and BSI-18 somatic symptom load (0.45).There was the same correlation pattern for item 1 (from 0.17 to 0.43), item 2 (from 0.17 to 0.43), item 3 (from 0.20 to 0.44), and item 4 (from 0.15 to 0.49) | Women (4.23) showed a higher JSS-4 total than men (3.37).There was a linear increase of JSS-4 total score from 1420 years (2.03) to 71 years (5.92).Not living with a partner (4.31) induced a higher JSS-4 score than living with a partner (3.47).JSS-4 total decreased as education level increased (from less education (8 years: 4.52 to university students: 1.74).Being retired (5.43) or unemployed (4.67) determined a higher JSS-4 total score than being a student (1.96) or worker (2.87).There was a linear decrease of JSS-4 total score from <1000 household income (5.78) to 2500 (2.81).Multivariate analysis showed that sleep problems were moderately linked (0.46) with global psychological distress in the specified model. As expected, female ( = 0.05 and 0.08, respectively), older ( = 0.24 and = 0.05, respectively), and low income ( = 0.18 and = 0.21, respectively) individuals were more likely to report sleep problems and psychological distress | According to the significant differences in JSS-4 scores between age groups and both sexes, norm values for the total sample as well as for each combination of age and sex separately were provided in percentile ranks:JSS-4 score = 0 corresponded to 33 percentile in total sample; JSS-4 score = 20 corresponded to 100 percentile in total sample | German |
| Manzar et al., 2018 [71]: LSEQ-M | A total of 424 Ethiopian university students (74 females); mean age of 21.87 years | 1-factor model with cumulative variance rule > 40%. 2-factor model with eigenvalue > 1 and scree plot: F1 (items getting to sleep 13, quality of sleep 12) and F2 (items awake following sleep 12, behaviour following wakening 12). The behaviour following wakening item 3 did not load in any factor.In confirmatory analysis no model had the best fit values even if the original 4-factor correlated model performed best in some values but not all | Cronbachs alpha was 0.84.Item-total correlations ranged from 0.60 to 0.69 | Based on GAD-7 score, normal participants had higher scores than those with moderate anxiety for LSEQ-M total score (66.92 vs. 52.65, respectively) and for all items with the exception of behavior, following wakening item 2 | ROC curve with LSEQ-M score cut-off value of 52.6, with AUC = 0.95, sensitivity = 94% and specificity = 80% | Ethiopian (Mizan) |
| Ricketts et al., 2019 [73]: SLEEP-50 | A total of 234 patients with Trichotillomania (227 females; mean age of 32.30 years), 170 patients with Excoriation disorder (162 females; mean age of 36.40 years) and 146 healthy adults (145 females; mean age of 38.60 years) | Trichotillomania: 9-factor model with Sleep Apnea (items 18; factor loadings range 0.410.89), Insomnia (items 916; factor loadings range 0.500.90), Narcolepsy (items 1721; factor loadings 0.520.69), Restless Legs/Periodic Limb Movement Disorder (items 2228; factor loadings range 0.490.95), Circadian Rhythm Sleep Disorder (items 2628; factor loadings range 0.490.73), Sleepwalking (items 2931; factor loadings range 0.560.84), Nightmares (items 3236; factor loadings range 0.390.65 with poor loading for item 35); Factors influencing sleep (items 3743; factor loadings range 0.370.80 with poor loading for item 39), Impact of sleep complaints on daily functioning (items 4450; factor loading range 0.590.94).Inter-factor correlations ranged from 0.21 to 0.76).Excoriation disorder:9-factor model with Sleep Apnea (items 18; factor loadings range 0.320.80), Insomnia (items 916; factor loadings range 0.630.83), Narcolepsy (items 1721; factor loadings 0.540.83), Restless Legs/Periodic Limb Movement Disorder (items 2228; factor loadings range 0.640.92), Circadian Rhythm Sleep Disorder (items 2628; factor loadings range 0.440.70), Sleepwalking (items 2931; factor loadings range 0.591.12), Nightmares (items 3236; factor loadings range 0.360.58 with poor loading for item 35); Factors influencing sleep (items 3743; factor loadings range 0.170.87 with poor loading for item 39), Impact of sleep complaints on daily functioning (items 4450; factor loading range 0.690.86).Inter-factor correlations ranged from 0.81 to 0.81) | Trichotillomania:Cronbachs alpha for the full scale was 0.91. Alphas for the individual subscales were:Sleep apnea (0.70), insomnia (0.85), narcolepsy (0.47), restless legs/PLMD (0.74), circadian rhythm sleep disorder (0.55), sleepwalking (0.39), nightmares (0.65), factors influencing sleep (0.56), and impact of sleep complaints on daily functioning (0.87).Excoriation disorder:Cronbachs alpha for the full scale was 0.89. Alphas for the individual subscales were:Sleep apnea (0.67), insomnia (0.85), narcolepsy (0.63), restless legs/PLMD (0.74), circadian rhythm sleep disorder (0.47), sleepwalking (0.66), nightmares (0.66), factors influencing sleep (0.41), and impact of sleep complaints on daily functioning (0.86) | Trichotillomania: there were correlations between SLEEP-50 overall complaints (0.71) and SLEEP-50 impact (0.63) subscales and the global PSQI. Similarly, correlations were found between SLEEP-50 overall complaints (0.62) and SLEEP-50 impact (0.60) subscales and PSQI overall sleep quality subscale (ranging from 0.16 to 0.75).Excoriation disorder: correlations were present between SLEEP-50 overall complaints (0.58) and impact (0.56) subscales and the global PSQI. Similarly, correlations were found between SLEEP-50 overall complaints (0.44) and impact (0.60) subscales and PSQI overall sleep quality subscales (ranging from 0.10 to 0.65) | There were differences between groups based on SLEEP-50 cut-off scores ( 15) for sleep apnea (trichotillomania 17.1%, excoriation 19.7% and control 6.5%), narcolepsy (trichotillomania 32.9%, excoriation 36.3% and control 16.1%), restless leg/periodic limb movement disorder (trichotillomania 19.7%, excoriation 24.4% and control 11.4%), circadian rhythm sleep disorder (trichotillomania 13.8%, excoriation 12.1% and control 5.1%) and with more than one sleep disorder (trichotillomania 63.6%, excoriation 66.5% and control 39.0%) | English (American) |
