Disruptions in Sleep Health and Independent Associations with Psychological Distress in Close Family Members of Cardiac Arrest Survivors: A Prospective Study

Abstract

Background:

While recent guidelines have noted the deleterious effects of poor sleep on cardiovascular health, the upstream impact of cardiac arrest–induced psychological distress on sleep health metrics among families of cardiac arrest survivors remains unknown.

Methods:

Sleep health of close family members of consecutive patients with cardiac arrest admitted to an academic center (August 16, 2021–June 28, 2023) was self-reported using the Pittsburgh Sleep Quality Index (PSQI). The baseline PSQI, focused on sleep in the month before cardiac arrest, was administered during hospitalization and repeated 1 month after cardiac arrest alongside the Patient Health Questionnaire-8 (PHQ-8) to assess depression severity. Multivariable linear regressions analyzed associations between total PHQ-8 scores and changes in global PSQI scores between baseline and 1 month, with higher scores indicating deterioration. A prioritization exercise explored potential interventions categorized into the family’s information and well-being needs to reduce psychological distress.

Results:

In our sample of 102 close family members (mean age 52 ± 15 years, 70% female, 21% Black, 33% Hispanic), mean global PSQI scores showed a significant decline between baseline and 1 month after cardiac arrest (6.2 ± 3.8 vs. 7.4 ± 4.1; P < .01). This deterioration was notable for sleep quality, duration, and daytime dysfunction. Higher PHQ-8 scores were significantly associated with higher change in PSQI scores after adjusting for family members’ age, sex, race/ethnicity, prior psychiatric history, and patient’s discharge disposition (B = 0.4 [95% CI 0.24–0.48]; P < .01, β = 0.5). Most families expressed a higher priority for information-based interventions over well-being needs to help alleviate psychological distress during the first month following cardiac arrest (76% vs. 34%, P < .01).

Conclusions:

A significant sleep health decline was observed among close family members of cardiac arrest survivors during the acute period, with psychological distress associated with this disruption. Understanding these temporal associations will help guide the development of targeted interventions to support families during this uncertain time.

Introduction

The American Heart Association’s Life’s Essential 8 guidelines¹ underscore the critical role of sleep in shaping cardiovascular health.^2,3 Close family members of critically ill patients are significantly susceptible to sleep disturbances.^4–7 Previous investigations have highlighted poor sleep quality⁴ and daytime sleepiness⁷ in approximately half of the family members during the hospitalization of their loved one’s critical illness, with one study reporting persistent sleep disturbances among this group.⁶ While these studies examined the impact of psychological distress and feelings of uncertainty on the sleep of informal caregivers in general critical care settings, there has been limited research in the context of cardiac arrest. A recent qualitative survey study⁸ in a convenience sample shed light on disturbances in sleep among family members affected by cardiac arrest, but systematic quantitative research remains limited.

The unique experience of cardiac arrest profoundly impacts families, especially those who witness or participate in resuscitative efforts.^9,10 Close family members often endure psychological distress at levels equal to, if not greater than, survivors^11–13 owing to the suddenness of the event, fear of recurrence, and ensuing life changes.^14,15 Moreover, the persistent uncertainty^9,16,17 surrounding prognosis and recovery exacerbates long-term mental health challenges, including depression, generalized anxiety, and post-traumatic stress disorder (PTSD), persisting even 1 year after the event in some family members.¹⁷ Given the predictive value of distress and poor sleep for poor post–cardiac events prognosis,¹⁸ understanding their interplay is paramount. The bidirectional relationship between poor sleep and distress^19–21 necessitates holistic interventions targeting both aspects. Understanding the interplay between sleep patterns and distress post-cardiac events^22,23 could inform the development and implementation of responsive sleep interventions, particularly for the families of millions of cardiac patients hospitalized annually. Moreover, sleep health’s association with psychological health,²³ social determinants of health,^24,25 and cardiovascular health^2,3 highlight its broader implications for cardiovascular health disparities. Previous studies have suggested that racial and ethnic minorities and socioeconomically disadvantaged individuals may be disproportionately affected by suboptimal sleep patterns linked to adverse health outcomes.^26,27 To address these knowledge gaps, we conducted a prospective study among a racially and ethnically diverse group of family members of cardiac arrest survivors at a tertiary care center in New York City. Our objectives were (1) to assess changes in sleep health metrics, including sleep quality, duration, and daytime alertness 1 month before and after cardiac arrest; (2) to quantify the independent effects of psychological distress markers (ie, the severity of depression [primary predictor], generalized anxiety, and PTSD) on sleep health; and (3) to identify intervention targets for prioritization in this population to potentially alleviate psychological distress and enhance postcardiac event care.

Methods

Study Design

An observational longitudinal cohort study

Participants

Participants were identified using the daily screening logs of a National Institutes of Health–funded research study (R01 HL153311) recruiting consecutive patients with cardiac arrest admitted between August 16, 2021 and and June 28, 2023 to 8 intensive care units at the Columbia University Irving Medical Center. Enrolled participants were close family members of adult patients age 18 years or older admitted with either in-hospital or out-of-hospital cardiac arrest.

As described by us previously,^28,29 to be classified as a “close family member,” participants were required to be either the patient’s designated health care proxy or someone with a close, immediate relationship to the patient who was present at the bedside during the consent process. Simply being present at the bedside was not sufficient; in cases in which multiple individuals were present, they were asked to specify who the patient’s primary contact or caregiver was. This procedure helped identify those individuals who were most closely connected to the patient and most affected psychologically by the traumatic event.

Exclusion criteria applied to participants who (1) experienced bereavement during the study period, that is, the patient died within 30 days of cardiac arrest; (2) were unavailable for in-person consent during working hours; or (3) were neither English nor Spanish speaking.

Study Assessments

Eligible family members reported demographics, medical and psychiatric history, and psychosocial risk factors through an intake questionnaire before hospital discharge. Measures of psychological distress were assessed 1 month after cardiac arrest via telephone or in-person. Sleep was measured at two time points: (1) baseline, during patients’ intensive care unit (ICU) admission after cardiac arrest; and (2) 1 month after cardiac arrest, a time point when most patients were discharged to home or facility. All patient-related details were obtained through electronic medical records. The Columbia University Institutional Review Board approved the study protocol. This study adhered to the STROBE guidelines for reporting cohort studies (see Supplementary Methods).

Measures

Sleep Health:

The Pittsburgh Sleep Quality Index (PSQI), a validated 19-item questionnaire,³⁰ evaluated 7 components of sleep health over the previous month: sleep quality, sleep latency, duration, habitual sleep efficiency, sleep disturbance, use of sleep medication, and daytime dysfunction. A baseline assessment during hospitalization was administered to assess habitual sleep during the month before the occurrence of cardiac arrest. A follow-up assessment captured sleep health during the month after cardiac arrest (see Supplementary Methods). Scores ranged from 0 (no difficulty) to 3 (severe difficulty) and the component scores were summed to produce a global score (range 0–21). The PSQI has a sensitivity of 89.6% and a specificity of 86.5% for identifying poor sleep. Higher scores indicated poorer sleep with a PSQI score >5, indicating overall poor sleep health. Participants indicated a preference to complete the PSQI in person or via telephone.³¹ The primary outcome was the change in global sleep health score from baseline to 1 month after cardiac arrest. A greater change indicates a worsening in the severity of sleep health. A secondary outcome was a global sleep health score 1 month after cardiac arrest.

Depression:

At 1 month after cardiac arrest, the Patient Health Questionnaire-8 (PHQ-8) was utilized to assess depressive symptom severity in the past 2 weeks about an identified traumatic experience, cardiac arrest of a loved one. Participants responded to the 8 Likert-type items via telephone or in person, with responses associated with a score: “not at all” (0), “several days” (1), “more than half the days” (2), and “nearly every day” (3). The subscores were summed to get a final score between 0 and 24. The PHQ-8 has good validity and reliability for detecting major depression, with a sensitivity of 88%, a specificity of 88%, and a high Cronbach’s alpha value (0.89).³²

Generalized Anxiety:

The Generalized Anxiety Disorder-2 (GAD-2) survey is a validated shorter version of GAD-7, using only the first 2 questions to screen for general anxiety symptoms. It has excellent psychometric properties of the GAD-7, with high sensitivity (86%) and specificity (83%).³³

Post-traumatic Stress:

The PTSD Checklist (PCL-5) is an extensively validated 20-item scale developed by the National Center for PTSD that corresponds to Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5) criteria for PTSD. The PCL-5 has adequate test-retest reliability and excellent sensitivity/specificity for PTSD clinical diagnosis prediction.³⁴

Prioritization Exercise of Supportive Interventions

In the context of prioritizing supportive interventions post–cardiac arrest, proposed measures previously delineated³⁵ were formulated via a collaborative co-designing process involving primary stakeholders (see Supplementary Methods for Questionnaire). These interventions encompass 8 distinct categories, broadly classified as either information-centric (education on potential recovery, knowledge about cardiac arrest, access to care teams, understanding rehabilitation options) or well-being-centric (access to caregiver resources, self-care tools, connection with other caregivers, and professional psychotherapy). At 1 month after cardiac arrest, participants were described the 8 interventions and asked to assess their perceived helpfulness on a 5-point Likert scale ranging from “extremely helpful” to “not at all helpful.” Then, participants were prompted to indicate their preferred mode of intervention delivery (i.e., written materials, web-based platforms, in-person sessions, telephone consultations, mobile/computer applications). Last, they were tasked with prioritizing the top 3 interventions according to their perceived necessity in addressing their needs during the initial month of post–cardiac arrest.

Statistical Analyses

Sleep health metrics between the two assessments were compared using chi-square and t tests.

The association between cardiac arrest–induced depression and sleep health was examined in an unadjusted and adjusted linear regression model with total PHQ-8 score as the primary predictor and change in global PSQI score (1-month PSQI score—baseline PSQI score) as the primary dependent variable. Following the recommended guidelines, we selected covariates a priori.³⁶ Based on published findings of factors that might confound the association between psychological distress and sleep health, Model 1 included the family’s demographics (age, sex, race/ethnicity),^7,37,38 and baseline global PSQI score. Model 2 also included the presence of prior psychiatric history.^6,29,39–41 The patient’s discharge disposition,^6,35 reflecting post–acute care needs or any potential significant factors listed in Table 1 that showed statistical significance (P< .01) with the primary outcome were added in Model 3. Factors considered were (1) family member attributes (eg, marital status, relationship to the patient); (2) psychological risk factors (eg, whether family members had witnessed the cardiac arrest and factors associated with positive psychological well-being, including optimism, purpose in life, or current use of spirituality as a coping mechanism); (3) patient-related characteristics (eg, age, sex, health insurance, location of arrest, length of ICU stay); and (4) hospital-related outcomes (eg, received a tracheostomy, discharge functional status).

Table 1.

Characteristics of Family Members of Cardiac Arrest Survivors (N = 102).

	% (N)
Family Member Attributes
Age, years (Mean ± Standard Deviation)	52±15
Female Sex	70 (71)
Race/ethnicity
Non-Hispanic White	40 (41)
Hispanic	33 (34)
Black	21 (21)
Other	6 (6)
Language
English	88 (90)
Spanish	12 (12)
Marital Status
Never married	25 (25)
Domestic partnership	6 (6)
Married	56 (57)
Separated	5 (5)
Divorced	7 (7)
Prefer not to answer	2 (2)
Relationship with the Patient
Partner/spouse	34 (35)
Child	29 (30)
Parent	12 (12)
Sibling	17 (17)
Extended family or other	8 (8)
Premorbid either lived with the patient or provided active assistance	69 (67)
Educational Attainment
8th grade or less	1 (1)
Some high school	6 (6)
High school diploma or GED	11 (11)
Trade school/vocational school	1 (1)
Some college, no degree	25 (25)
College degree	31 (32)
Some graduate school, no degree	4 (4)
Graduate degree	20 (20)
Prefer not to answer	2 (2)
Occupational Status
Working now, full-time	42 (43)
Working now, part-time	14 (14)
Disabled, permanent or temporary	4 (4)
Temporarily laid off, sick leave, or maternity leave	3 (3)
Keeping house	4 (4)
Student	2 (2)
Unemployed, looking for work	13 (13)
Retired	18 (19)
Types of Comorbidities
Heart disease	6 (6)
Hypertension	29 (29)
Lung disease	4 (4)
Diabetes	11 (11)
Ulcer or Stomach disease	5 (5)
Kidney disease	3 (3)
Liver disease	0 (0)
Anemia or other blood disorders	6 (6)
Cancer	5 (5)
Musculoskeletal disorders	34 (32)
Overweight/Obesity	26 (25)
Prior Psychiatric condition (e.g., depression, anxiety, PTSS)	22 (22)
Number of Comorbidities
None	23 (23)
1-2	48 (48)
≥3	29 (29)
Prior Sleep Health, Global PSQI Score (Mean ± Standard Deviation)	6.2±3.9
One-month Sleep Health, Global PSQI Score (Mean ± Standard Deviation)	7.4±4.1
Witnessed CPR	19 (19)
Positive Psychological Well-being
Optimism (Mean ± Standard Deviation)	16 ±4
Purpose in Life (Mean ± Standard Deviation)	4.7±0.9
Use spirituality as a coping mechanism
Strongly agree	10 (10)
Agree	1 (1)
Neutral	38 (38)
Disagree	5 (5)
Strongly disagree	46 (46)
Perceived social support
Total score on MSPSS (Mean ± Standard Deviation)	69±15
Depressive Symptoms, Total PHQ-8 Score (Mean ± Standard Deviation)	7.0±5.5
Generalized Anxiety Symptoms, Total GAD-2 Score (Mean ± Standard Deviation)	2.8±2.1
Post-traumatic Stress Symptoms, Total PCL-5 Score (Mean ± Standard Deviation)	14.8±12.4
Patient Attributes
Age, years (Mean ± Standard Deviation)	61±16
Female sex	36 (37)
Independence in Daily Activities Prior to Cardiac Arrest
Home, unassisted	69 (70)
Home, assisted with activities of daily living	23 (23)
Institutionalized	9 (9)
Out-of-Hospital Cardiac Arrest	22 (22)
Length of ICU stay, days (Median, Interquartile Range)	14 (8 - 26)
Tracheostomy before discharge	33 (34)
Health Insurance
Uninsured or Medicaid	45 (46)
Medicare	27 (25)
Private	28 (28)
Functional Outcomes, Modified Rankin score (mRS) at Discharge
mRS-0	1 (1)
mRS-1	17 (17)
mRS-2	2 (2)
mRS-3	23 (24)
mRS-4	24 (25)
mRS-5	18 (18)
mRS-6	15 (15)
Discharge Disposition After Cardiac Arrest
Home	41 (42)
Facility (Acute rehab/Sub-acute rehab/LTAC)	44 (45)
Currently Hospitalized	15 (15)

GAD-2 indicates Generalized Anxiety Disorder 2; GED, General Education Development; ICU, intensive care unit; LTAC, long-term acute care; mRS, Modified Rankin Score; MSPSS, Multidimensional Scale of Perceived Social Support; PCL-5, PTSD Checklist for DSM-5; PHQ-8, Patient Health Questionnaire; PSQI, Pittsburgh Sleep Quality Index; PTSS, Posttraumatic stress syndrome.

Similarly, 2 separate analyses tested the associations of GAD and PTSD total scores with differences in global PSQI scores after adjusting for the covariates included in the final model for the PHQ-8.

Post-regression Analysis

After estimating both unstandardized (B) with 95% confidence intervals (CIs) and standardized beta (β) coefficients, to provide a comprehensive understanding of the relationships between depression and sleep health, we calculated (1) R² value to indicate the overall strength of the relationship and a measure of the model’s goodness of fit, (2) effect size for individual predictors using eta-squared (η²), and (3) confidence intervals for effect sizes to convey the precision of the estimates. Our models fulfilled assumptions for linear regressions. The variables did not present with multicollinearity; the variance inflation factors of the multivariate models were <2.

Sensitivity Analysis

We repeated our primary outcome analyses with PHQ-8 total score after excluding scores obtained on the sleep-related question to prevent bias resulting in overestimation of the association.

Power Analysis

Using the R² test in multiple linear regression, with α = 0.05, sample size 100, R² of 0.53, and 7 tested covariates, the estimated power was greater than 95%.

Secondary Outcomes

We then conducted similar analyses of PHQ-8, GAD-2, and PCL-5 total scores with global PSQI scores at 1 month.

Intervention Prioritization

Key measures and statistical analysis centered on the relative performance and ranking of the 8 interventions tested. We first compared the performance based on combined “very helpful to extremely helpful” responses on the Likert scale. The top 3 ranks were used as the key measure for individual intervention comparisons. Further categorization into 2 a priori groups of interventions—“information needs” versus “well-being needs” was based on the top-ranked assignment for individual interventions.

All statistical analysis was performed using STATA 18. A significance level of P < .05 was considered statistically significant.

Results

Study Population

Of 438 cardiac arrest admissions, 247 met exclusions. Of 191 eligible participants approached, 137 consented and 102 with 1-month outcomes data were analyzed (CONSORT Diagram, Supplementary Fig. 1). As shown in Supplementary Table 1, compared with 25 participants who either withdrew or did not complete a 1-month assessment, a higher proportion of the analyzed group had an education of college degree or higher (28% vs. 56%) and went home (12% vs. 43%). There were more deaths during hospitalization in the lost-to-follow-up group compared with the group analyzed after 1-month post-cardiac arrest (40% vs. 15%).

Close Family Members’ Attributes

Participants’ average age was 52 ± 15 years, with the majority identifying as female (n = 71, 70%). The cohort was diverse, comprising 40% (n = 41) non-Hispanic White, 21% (n = 21) Black, and 33% (n = 34) Hispanic participants. The most common relation to the patient was a spouse/partner (n = 35, 34%). A few participants, 12 (12%), were Spanish speaking only, and 19 (19%) witnessed cardiopulmonary resuscitation. Most participants reported 1 or more comorbid conditions (n = 79, 77%), with musculoskeletal disorders (n = 32, 34%), hypertension (n = 29, 29%), obesity (n = 25, 26%), and prior psychiatric history (n = 22, 22%) being most common (Table 1).

Patient Characteristics

Almost all patients lived at home before cardiac arrest (n = 93, 92%). After a median (interquartile range) ICU length of stay of 14 (8-26) days, 34 (33%) required tracheostomy, 58 (57%) had poor functional status (modified Rankin score >3) at hospital discharge, and less than half (n = 42, 41%) went home (Table 1).

Sleep Health and Its Components

The mean global PSQI score increased significantly from baseline to 1 month after cardiac arrest (6.2 ± 3.8 vs. 7.4 ± 4.1; P < .01; Table 1). The mean difference in PSQI scores was 1.3 ± 3.8. The average improvement in scores among 34% of participants was modest (1.9 ± 1), whereas 43% experienced worsening scores, which averaged 4.6 ± 3.3 (P < .01).

Of all PSQI components, sleep quality, sleep duration, and daytime dysfunction showed significant worsening from baseline to 1 month after cardiac arrest (Fig. 1).

Fig.1.

Mean PSQI subcategory scores of close family members of cardiac arrest survivors: premorbid evaluation versus 1 month post-arrest.

**denotes P < .05

There was a significant increase in the proportion of participants reporting poor sleep quality from baseline to 1 month after cardiac arrest (24% vs. 47%; P < .01). Among participants with good sleep quality at baseline (76%, n = 75/99), 31% (n = 23/75) shifted to poor sleep quality at 1 month.

Among participants with guideline-recommended sleep duration of ≥7 hours at baseline,⁴² 40% (n = 19/48) had worsening in their sleep duration 1 month after cardiac arrest (10% reported sleep duration of <5 hours, 15% with ≥5 and <6 hours, 15% with ≥6 and <7 hours).

Means of Depressive, Generalized Anxiety, and PTSD Symptom Scores 1 Month After Cardiac Arrest

The average PHQ-8, GAD-2, and PCL-5 scores at a median duration of 28.5 (interquartile range 10–63) days after cardiac arrest were 7.0 ± 5.5, 2.8 ± 2.1, and 14.8 ± 12.4, respectively.

Covariate selection for the multivariable-adjusted model

Apart from PHQ-8, GAD-2, and PCL-5 total scores, Hispanic ethnicity and patients’ discharge disposition to home showed significant (P < .01) bivariate associations with differences in global PSQI scores. All associations were adjusted for baseline global PSQI score. Since there were only 12% (n = 12) participants in the Spanish-speaking group, though statistically significant, it was not included in the multivariate model (Table 2).

Table 2.

Bivariate associations of various family member and patient characteristics with Differences in Sleep Health between baseline and one month after cardiac arrest (N=100)

	Coefficients	P-value
Family Member Attributes
Age, years	−0.04	0.09
Female Sex	−1.1	0.2
Race/Ethnicity
Non-Hispanic White	reference
Hispanic	2.8	<0.01
Black	0.9	0.3
Other	1.0	0.5
Primary Language (Spanish vs English)	3.5	<0.01
Marital status (Married/Domestic Partnership vs others)	−0.06	0.9
Relationship with the Patient
Partner/spouse	reference
Child	0.9	0.3
Parent	−0.6	0.6
Sibling	0.5	0.6
Extended family or other	−1.0	0.4
Pre-morbid either lived with the patient or provided active assistance	0.2	0.8
Education, College degree or higher vs others	−0.6	0.4
Occupation, Working full or part-time vs others	0.6	0.4
Number of Comorbidities
None	reference
1-2	0.7	0.5
≥3	0.3	0.8
Prior Psychiatric History (Yes/No)	0.06	0.9
Prior Sleep Health, Global PSQI Score	−0.4	<0.01
Witnessed CPR of their loved one (Yes/No)	1.3	0.2
Positive Psychological Wellbeing
Optimism	0.09	0.2
Purpose in Life	−0.5	0.2
Use spirituality as a coping mechanism, Disagree or Strongly Disagree vs others	0.3	0.4
Perceived social support, MSPSS Total score	−0.04	0.1
Depressive Symptoms, Total PHQ-8 Score	0.4	<0.01
Generalized Anxiety Symptoms, Total GAD-2 Score	0.8	<0.01
Post-traumatic Stress Symptoms, Total PCL-5 Score	0.09	<0.01
Patient Attributes
Age	0.007	0.8
Female sex	−0.03	1.0
Poor Health insurance (Uninsured/Medicaid vs others)	−0.9	0.2
Out-of-Hospital Cardiac Arrest	0.3	0.7
Length of ICU stay	0.004	0.8
Discharged with a Tracheostomy, (Yes vs No)	−0.3	0.7
Poor Functional Outcomes (modified Rankin score >3) at discharge	−0.2	0.7
Discharge Disposition after Cardiac Arrest
Home	reference
Facility (Acute rehab/Sub-acute rehab/LTAC)	−3.1	<0.01
Died during index hospitalization after study completion	−1.3	0.2

CPR cardiopulmonary resuscitation; GAD-2, Generalized Anxiety Disorder 2; ICU, intensive care unit; LTAC, long-term acute care; MSPSS, Multidimensional Scale of Perceived Social Support; PCL-5, PTSD Checklist for DSM-5; PHQ-8, Patient Health Questionnaire 8; PSQI, Pittsburgh Sleep Quality Index; PTSS, posttraumatic stress syndrome.

Association of Psychological Distress with Sleep Health

Higher PHQ-8 scores were significantly associated with greater change in total global PSQI scores (Table 3), both in the bivariate analysis after adjusting for baseline PSQI score (B = 0.4, 95% CI 0.2–0.5; P < .01) and in a multivariate model after adjusting for age, female sex, race/ethnicity, and discharge disposition (B = 0.3, 95% CI 0.2–0.5; P < .01, β = 0.5). The 95% CI for R² (0.53) ranged from 0.3 to 0.6, indicating a relatively precise estimate of the proportion of variance explained by the full model. The effect size (η²) for PHQ-8 was 0.2 (95% CI 0.1–0.4), indicating a moderate effect on the sleep health (Supplementary Table 2). Higher GAD-2 and PCL-5 total scores were significantly associated with greater differences in global PSQI scores (B = 0.6, 95% CI 0.3–0.9, P < .01, β = 0.4; and B = 0.1, 95% CI 0.02–0.1, P =.01, β = 0.2, respectively) in a multivariate model (Supplementary Tables 3 and 4).

Table 3.

Associations Between Depressive Symptoms in Close Family Members and Changes in Sleep Health Before and 1 Month After Cardiac Arrest

Covariates	Multivariate Model 1 Coefficient	95% CI	P value	Multivariate Model 2 Coefficient	95% CI	P value	Multivariate Model 3 Coefficient	95% CI	P value	Standardized Beta (β)
PHQ total score	0.4	(0.2, 0.5)	<0.01	0.4	(0.3, 0.5)	<0.01	0.3	(0.2, 0.5)	<0.01	0.5
Age	−0.003	(−0.04, 0.04)	0.9	−0.01	(−0.05, 0.03)	0.7	−0.004	(−0.04, 0.04)	0.8	−0.02
Female sex	−0.02	(−1.3, 1.2)	1.0	0.06	(−1.2, 1.3)	1.0	0.1	(−1.1, 1.4)	0.8	0.02
Non-Hispanic White	reference			reference
Hispanic	2.0	(0.6, 3.4)	<0.01	2.0	(0.7, 3.3)	<0.01	1.8	(0.4, 3.1)	0.01	0.2
Black	1.1	(−0.4, 2.6)	0.1	1.3	(−0.2, 2.8)	0.8	1.3	(−0.2, 2.7)	0.09	0.1
Other	1.6	(−0.7, 4.0)	0.2	1.4	(−0.9, 3.8)	0.2	1.1	(−1.2, 3.4)	0.3	0.07
Premorbid PSQI Total Score	−0.6	(−0.7, −0.4)	<0.01	−0.6	(−0.7, −0.4)	<0.01	−0.6	(−0.8, −0.4)	<0.01	−0.6
Prior Psychiatric History				−1.5	(−2.9, −0.2)	0.03	−1.5	(−2.9, −0.1)	0.03	−0.2
Disposition, Home							reference
Disposition, Facility							−1.4	(−2.7, −0.1)	0.04	−0.2
Hospitalized							−0.7	(−2.4, 0.9)	0.3	−0.07

Sensitivity Analysis

Higher PHQ-8 scores even after the exclusion of values on sleep-related questions were significantly associated with greater differences in total global PSQI scores after adjusting for family’s age, female sex, race/ethnicity, prior psychiatric history, and patient’s discharge disposition (B = 0.4, 95% CI 0.2–0.5, P < .01, β = 0.5).

Secondary Outcome

We found similar significant associations in an adjusted cross-sectional model of 1-month PHQ-8, GAD-2, and PCL-5 total scores with global PSQI score at 1 month (Supplementary Tables 5–8).

Prioritization Results of Supportive Interventions

In the month following the cardiac arrest, most participants (76%, n = 72) preferred 1 of the 4 information-based interventions (education on potential recovery, knowledge about cardiac arrest, access to care teams, and understanding rehabilitation options) as opposed to well-being needs (24%, n = 23) including access to caregiver resources, self-care tools, connection with other caregivers, and professional psychotherapy.

The top 3 interventions rated “very helpful’ or “extremely helpful” as a supportive resource were access to the care team (94% of participants, n = 89/95), education on potential recovery (93%, n = 88/95), and understanding rehabilitation options (87%, n = 83/95; Fig. 2).

Fig.2.

Perceptions of helpfulness among close family members during cardiac arrest hospitalization and beyond, by intervention.

Of 760 responses, written information (27%, n = 204) and web-based information (26%, n = 194) were the most preferred modes of delivery, whereas a phone app resource received the least preference (11%, n = 83). Specifically, written or web-based information was the most preferred mode of delivery for all intervention resources except having access to the care teams and professional psychotherapy, for which participants preferred phone calls (Supplementary Fig. 2).

The top 4 interventions with the highest frequency of appearance in participants ranking as either first, second, or third were (A) access to the care team for information beyond hospital discharge (62%, n = 59/95); (B) education on the potential neurologic, physical, and emotional recovery expected during hospitalization and up to 1 year after discharge (55%, n = 52/95); (C) knowledge about cardiac arrests and their distinctions from heart attacks and strokes (41%, n = 39/95); and (D) understanding rehabilitation options and their role in the overall recovery (41%, n = 39/95; Fig. 3).

Fig.3.

Listing of 8 interventions with response counts for first, second, and third rankings by close family members.

Discussion

This study is among the earliest longitudinal, systematic, quantitative assessments of sleep health in close family members of survivors of cardiac arrest. Our findings confirm that family members experience a significant decline in sleep health within the initial month after the event of their loved one.

In one of the few studies assessing sleep quality using PSQI, Choi et al.⁶ evaluated 28 family caregivers of ICU survivors. They found that over half continued to experience poor sleep 2 months after discharge, highlighting the lasting impact of this experience. The study reported a mean PSQI score of 6.9 ± 4.1 at ICU admission, stable at 6.8 ± 4.6 up to 2 weeks post-discharge, and slightly decreasing to 6.2 ± 3.6 at 2 months. Similarly, our cohort had a premorbid mean PSQI score of 6.2, comparable to other PSQI validation studies in non-clinical populations,⁴³ which increased to 7.4 ± 4.2 1-month post-event with the highest quartile of scores ranging from 10 to 16.5, indicating a greater impact on sleep health. Understanding these patterns can inform targeted interventions in the inpatient setting.

Participants reported significant disturbances in sleep duration and daytime dysfunction in addition to subjective sleep quality. Among those who achieved the recommended sleep duration of ≥7 hours, 40% experienced worsened sleep duration 1 month post-event, up from 24% at baseline. This may reflect the critical care context, in which family members face life-and-death decisions in the ICU and afterward. Our findings align with previous research^6,7 showing that poor nighttime sleep leads to excessive daytime sleepiness and impaired functioning. These sleep disturbances pose challenges for caregiving and may contribute to post-intensive care syndrome in families, highlighting the need for targeted interventions to improve their well-being.

Our main finding is that the decline in sleep health among close family members significantly correlates with depression symptoms in the month following a cardiac event. We also found statistically significant associations between sleep deterioration and symptoms of GAD and PTSD. These results highlight the intricate relationship between psychological distress and sleep disturbances after sudden, traumatic events, suggesting opportunities for intervention. Our research adds to the limited evidence of high sleep disturbance prevalence among family members in critical care settings.^4,6 In one of the only cross-sectional, survey-based, qualitative studies, 95% of family members of survivors of cardiac arrest reported persistent psychological distress, with 1 in 4 experiencing poor sleep after discharge.⁸

One noteworthy finding is the increased susceptibility of Hispanic participants to sleep health issues compared with non-Hispanic Whites, a trend also seen in population-health-based studies.^27,44–46 At 1 month, only 9% of Hispanic participants reported good sleep, compared to 56% of non-Hispanic Whites (Supplementary Table 9). Furthermore, Hispanic ethnicity was significantly related to declining sleep health over time, with these associations holding across all models for the studied psychological distress indicators. These disparities highlight the role of sleep and psychosocial factors in cardiovascular health inequities.²³ Although sleep variations were noted between English and Spanish speakers, the small sample size (n = 12) calls for further research.

Our study found that discharge to a rehabilitation facility, rather than home, was associated with improved sleep health. This aligns with previous research⁶ indicating that families of patients discharged home within 2 weeks of ICU discharge experienced poorer sleep than those discharged 2 months later. Early home discharge may increase stress by overwhelming caregivers, while rehabilitation facilities provide reassurance of continued professional care.²⁹ Future studies should investigate how different post-ICU transitions affect families’ sleep to identify potential intervention targets during this vulnerable period.

Our third objective was to explore interventions addressing the root causes of psychological distress among family members during the acute period. Family members predominantly prioritized information-based interventions to alleviate uncertainty and distress, potentially improving sleep health.^4,5 This finding aligns with themes from a qualitative study on in-hospital cardiac arrest,⁴⁷ a National Institutes of Health–funded work-shop,⁴⁸ and our previous work³⁵ on families’ needs after such events. Notably, in that study, while families initially prioritized information, their need for psychological support grew significantly 2 to 6 months post-discharge, emphasizing the importance of ongoing support and the evolving nature of their needs.

Strengths

This study has several strengths. By focusing on family members of survivors of cardiac arrest—an understudied group—we provide valuable insights into their unique experiences and needs. Our adequate power and prospective design enhance the internal validity of our findings. Despite a modest sample size, we observed a significant 4.6-point increase in PSQI scores between the 2–time points, where changes over 4 points are clinically significant in other populations.⁴⁹ The diverse demographic of our participants strengthens the external validity, and our dyadic approach by including both patient and family attributes allowed us to comprehensively examine associations between psychological distress and sleep health. Finally, our analysis of sleep health decline in the first month post–cardiac arrest offered valuable methodological insights to investigate temporal dynamics of sleep disturbances in this acute period.

Limitations

Our study has several potential limitations. Using the PSQI as our primary metric for sleep health may introduce recall bias; future research should include objective assessments, such as wrist actigraphy. While we examined changes in sleep metrics and their associations with psychological distress, we did not assess novel predictors of cardiometabolic health, such as sleep regularity.⁵⁰ Additionally, our analysis was limited to the first-month post-cardiac event. Longitudinal studies with extended follow-up could provide a clearer picture of sleep trajectories and their interplay with psychological distress.

Moreover, we lacked baseline assessments of psychological distress prior to cardiac arrest, which limits our ability to track emotional changes over time. This limitation stems from the acute nature of ICU conditions. However, prior psychiatric history has been used as a proxy for assessing psychological impact, as it strongly correlates with distress after traumatic events.^39–41 Our findings showed that baseline PSQI scores were significantly higher in family members with a prior psychiatric history (n = 22, 7.8 ± 4.4) compared with those without (n = 78, 5.7 ± 3.6, P = .02), consistent with existing research.⁶ Future studies could enhance the understanding of temporal associations by using acute period scores as baselines to inform intervention development.

Future Directions

The study showed a significant association between poor sleep health and elevated levels of psychological distress in close family members. However, this study is observational and not equipped to conduct mediation analysis or claim to provide any evidence of causality. While our analysis controlled for several confounding factors, residual confounding may still influence the observed relationship. Future studies might employ experimental designs to evaluate psycho-education interventions or cognitive behavioral therapy²³ in addressing the mental and sleep health needs of family members. One ongoing study (ClinicalTrials.gov ID NCT06048068) is testing the feasibility and acceptability of an information website aimed at reducing psychological distress and caregiver burden among close family members of patients with cardiac arrest while testing uncertainty as a potential mechanism. Future research might also study the long-term effects of poor sleep following a loved one’s cardiac arrest on cardiovascular health, as a growing body of epidemiologic evidence has linked insufficient sleep and poor sleep quality to heightened risks of all-cause mortality and cardiovascular issues.^2,3,51 Whether psychological factors act as mediators of the relationship between sleep and cardiovascular disease or sleep changes mediate the relationship between psychological distress from traumatic events²³ and known increased cardiovascular risk^39,52 is not known and is actively been investigated in survivors of cardiac arrest.⁵³

Conclusions

We found significant sleep health deterioration among close family members 1 month after their loved one’s cardiac arrest. Cardiac arrest–induced psychological distress had a significant association with worsening in multiple aspects of sleep health. We found racial and ethnic disparities in these associations, with Hispanic families showing heightened susceptibility to sleep disruptions. Families prioritized interventions addressing information-based needs in the first month after cardiac arrest to reduce uncertainty and psychological distress. Our research framework, which integrates knowledge, methods, and measures from psychology and sleep research, has the potential to advance cardiovascular disease prevention and promote a more holistic approach to managing critically ill patients by accounting for the secondary impact of the disease on the psychological and cardiovascular health of their family members. Further research is needed to guide the development of comprehensive support strategies tailored to the multifaceted needs of families affected by cardiac arrest.

Brief Lay Summary

To the best of our knowledge, this study is one of the first to comprehensively assess sleep health in family members of survivors of cardiac arrest over time. It found a significant decline in several key components of sleep health within the first month after the event. Family members reported high levels of depression, anxiety, and PTSD symptoms that were significantly related to these sleep issues. Families prioritized information about their loved one’s condition and recovery over resources for their emotional well-being. The study emphasizes the need for targeted information resources during hospitalization to support families, which may enhance overall well-being and sleep health.

How The Study Results Apply to Stakeholders

• Close family members of critically ill patients, a critical but often overlooked group, experience suboptimal sleep health, and psychological distress may contribute to it.

• Families of cardiac arrest survivors prioritized interventions that address their information needs over well-being needs to reduce psychological distress in the month following the event.

• The study highlights the need for targeted, accessible information resources during hospitalization to address uncertainty, psychological burden, and poor sleep health.

Biography

Isabella M. Tincher