Mental health and alcohol use among patients attending a post-COVID-19 follow-up clinic: a cohort study

Overview

A prospective cohort study design was used encompassing baseline assessment of participant outcomes at 2–4 months following an initial visit to the hospital’s post-COVID-19 follow-up clinic, and subsequent follow-up assessment at 7–14 months. The study was informed by and conducted according to the ‘Strengthening the reporting of observational studies in epidemiology (STROBE) statement’ guidelines³⁰, and was approved by the MMUH Research Ethics Committee (Ref # 1/378/2141). Written informed consent for publication of the participants details was obtained from the participants.

Setting

The study was conducted at the post-COVID-19 follow-up clinic at the MMUH, in North Inner-City Dublin, Ireland, over fourteen months through June 2020-August 2021. The post-COVID-19 follow-up clinic provides care for patients experiencing long-term COVID-19 health issues. It specializes in the delivery of clinical assessment for post-COVID-19 populations and the facilitation of referral to appropriate specialist care services where required.

Participants

Approximately 12–15 patients attended the post-COVID-19 follow-up clinic weekly during the enrolment period resulting in an overall attendance estimate of 250–300 patients. Patients were eligible for inclusion in the study if they were adults attending the clinic during the study enrolment period. Participants were also required to have received laboratory confirmed and/or clinically diagnosed COVID-19. It is not clear how many of the clinic’s patients met these study inclusion criteria and / or were invited to take part in the study. Clinic patients had either been hospitalised with COVID-19, been placed on a COVID-19 ambulatory home monitoring programme or had been referred to the clinic by local general practitioners (GPs).

Procedure

Participating patients completed identical healthcare professional / researcher administered questionnaires at Time 1 (2–4 months after an initial clinic visit) and Time 2 (7–14 months after initial clinic visit). Participants completed a large questionnaire as part of a wider research project, but only responses relating to participants’ core demographics (age & sex), acute COVID-19 severity (illustrated by acute COVID-19 healthcare service utilization trends), mental health status, and alcohol usage were examined in this study.

Instruments

Participants were asked to indicate their age and sex details, as well as whether they had previously been diagnosed with an affective disorder. Questions regarding healthcare utilization asked participants whether they had been admitted to hospital / ICU, and if they had been readmitted to hospital following an initial acute COVID-19 hospital stay. Where applicable, questions enquired as to the length of participants’ hospital / ICU stays, and they also asked whether participants had attended GPs within seven and / or 30 days of an acute COVID-19 related hospital discharge. Participants’ mental health was measured using standardized depression, anxiety, and post-traumatic stress scales, all of which have previously been used in Long COVID research^31–33. Depression was measured using the PRIME-MD ‘Patient Health Questionnaire’ (PHQ-9)³⁴, anxiety was assessed using the ‘PRIME-MD Generalized Anxiety Disorder’ questionnaire (GAD-7)³⁵, and post-traumatic stress was evaluated using the 22-item version of the ‘Impact of Events Scale Revised’ instrument (IES-R)³⁶. Alcohol usage was measured using the AUDIT-C brief screening tool for alcohol misuse³⁷.

Data analysis

Data was analysed using descriptive and inferential statistics in IBM SPSSv26.0³⁸. Non-parametric statistics were used throughout due to the non-normal nature of the data. Participants were excluded from analyses where ≥20% of relevant questionnaire responses were missing, and mean data was imputed for the standardized questionnaires’ total score figures when missing data was present but below the ≥20% cut-off point. The results outlined demonstrate study recruitment and retention rates, missing data statistics, patient demographics, psychiatric medical history, healthcare utilization trends, the prevalence and duration of psychiatric/alcohol use outcomes, and risk factors for adverse psychiatric/alcohol use outcomes.

Sample demographics and healthcare utilization experiences

The sample’s median age at baseline was 43.45yrs (IQR = 21.18). There were 105 (68.6%) females and 48 (31.4%) males. Seventeen of 153 participants (11.1%) reported that they had previously being diagnosed with an affective disorder. Sixty-seven (43.8%) of 153 patients were admitted to hospital with acute COVID-19, nine of the these (13.4%) were admitted to ICU, and 17/67 (25.4%) had been readmitted to hospital following their initial acute COVID-19 hospital stay. The median initial hospital stay was seven days (IQR = 13), the median ICU stay was 26 days (IQR = 20.5), and the median readmission stay was three days (IQR = 4.75). Sixteen patients (23.9%) reported visiting a GP within seven days of their initial hospital discharge, and 26 (38.8%) reported doing so within 30 days of initial hospital discharge.

PHQ-9, GAD-7, IES-R, and AUDIT-C outcomes

Table 1 shows the median (IQR) Time 1 and Time 2 scores for the PHQ-9, GAD-7, IES-R, and AUDIT-C. Table 2 outlines the instruments’ Time 1 and Time 2 prevalence scores per clinical category, as well as ‘symptoms’ vs ‘no symptoms’ Time 1 and Time 2 relative risk statistics. Wilcoxon signed-rank tests identified no statistically significant differences between Time 1 and Time 2 for PHQ-9, GAD-7, and IES-R median scores. A statistically significant difference was observed between Time 1 and Time 2 median scores on the AUDIT-C measure, with Time 2 scores being significantly higher (Z = -5.291, p = .000).

Risk factor analysis

As no differences were observed between Time 1 and Time 2 outcomes on the PHQ-9, GAD-7, and IES-R measures, risk factor analyses relating to these measures were conducted for Time 1 scores only. As test outcomes highlighted significant differences between Time 1 and Time 2 AUDIT-C scores, risk factor analyses were conducted for both AUDIT-C time periods.

Age, sex, and acute-COVID-19 severity did not influence median outcomes on the PHQ-9, GAD-7, IES-R, and AUDIT-C measures for most part. However, participants who were admitted to hospital with acute COVID-19 were statistically more likely to have higher PHQ-9 scores (U = 2106.5, p = .041), participants attending GPs within 30 days of hospital discharge were more likely to have higher GAD-7 (U = 298.5, p = .031) and IES-R scores (U = 247.0, p = .006), and a positive statistically significant relationship was observed between IES-R scores and length of ICU stay (r = .737, p = .023). Participants who reported having been previously diagnosed with an affective disorder had significantly higher PHQ-9 (U = 314.000, p = .000), GAD-7 (U = 508.5, p = .000), and IES-R (U = 575.000, p = .002) scores. There were no significant differences between affective disorder categories for the Time 1 and Time 2 AUDIT-C outcomes.

Summary of findings

This study aimed to investigate the occurrence, duration, and determinants of long-term psychiatric problems and problematic alcohol use among patients attending a post-COVID-19 follow-up hospital clinic at the MMUH in Dublin, Ireland. Mental health concerns and problematic alcohol use were both evident and persistent in the study sample. Depression, anxiety, and PTSD issues were notably more common among participants who had previously been diagnosed with an affective disorder, and in some instances, these issues were more common among patients who received acute COVID-19 related hospital care (depression), ICU care (PTSD) and subsequent GP/primary care follow-up (anxiety and PTSD).

Strengths and limitations

The post-COVID-19 follow-up clinic facilitated ongoing access to a population sub-group that is hard to reach, and its staffs’ efforts also ensured healthy participant recruitment and retentions rates^39,40, as well as low levels of missing data⁴¹. The study design and reporting benefitted from applying the STROBE guidelines³⁰ which ensured a trustworthy methodological framework to follow, and greater transparency in terms of reporting the procedures employed during the data collection and analysis processes.

As for study limitations, our sample was relatively small, and out of necessity, purposeful/convenient sampling methods, rather than randomization techniques, were used for recruitment. These factors may have limited the extent to which study’s findings are generalizable to wider Long COVID / post-severe acute COVID-19 populations. It may also have been preferable to use more direct methods of measuring acute COVID-19 severity (e.g., symptomology)⁴² instead of, or in combination with, the healthcare utilization surrogate endpoints employed.

Comparisons with existing literature

Previous literature regarding the prevalence of psychiatric issues in Long COVID populations is inconsistent. When considering a range of moderate to severe psychiatric issues, especially depression and PTSD, this study’s findings align most closely with Schou et al.’s¹⁶ pooled estimation range of 20–30%. This study’s findings also reflect those of COVID-19 era studies examining the prevalence of depression and anxiety in COVID-19 pandemic in the Irish general population^43,44.

Further, and as previously mentioned, we believe this study is the first to examine alcohol use among Long COVID populations. The high problematic alcohol use figures observed are both alike (Time 1) and in excess of (Time 2) previously reported data for the general Irish population using the AUDIT-C instrument⁴⁵. There was no evidence suggesting that the AUDIT-C outcomes observed in this study were influenced by acute and/or Long COVID effects, or by other factors such as pre-existing mental illness, or the pandemic’s adverse psychosocial impacts⁴⁶.

In line with the consensus of previous research, this study’s results did not suggest that age is a risk factor for persistent COVID-19 mental health issues. Likewise, the results did not support the relatively few claims made that male or female sex is linked to adverse mental health outcomes in persistent COVID-19 populations^21,22. The findings strongly support claims that Long COVID patients with pre-existing psychiatric diagnoses are more likely to experience ongoing mental health difficulties²⁴. Moreover, this study’s findings provide some evidence supporting previous claims that severity, as measured by healthcare utilization experiences in this instance, is an indicator of persistent psychiatric issues in affected populations^47,48.

Whilst this study’s sample size was much smaller than some published studies examining psychiatric post-acute COVID-19 sequelae^48–50, it is comparable to most studies conducted on the topic so far. This study is also one of many cohort studies in this area, although its follow-up period of 7–14months exceeds those of all the studies reported by Schou et al.¹⁶ in their recently published systematic review of psychiatric and neuropsychiatric post-acute COVID-19 sequelae. Further, this study’s finding that the prevalence of psychiatric issues typically remained stable over long periods of time appears to be at odds with the findings of previous robust studies^15,16,49. It remains to be seen whether future large-scale studies with equally comparable or lengthier follow-up periods align more closely with this study’s findings regarding symptom duration.

The psychiatric instruments employed in this study have also been used by several other studies investigating the research topic^{21,23,32,51–53}, although an enormous variety of methods have been adopted for classifying psychiatric outcomes in Long COVID study populations to date. It is possible that instrument selection in this and other studies influenced study outcomes. Having said this, for all their differences, the range of validated psychiatric instruments used to date should be sensitive and specific enough to capture a reasonably correct depiction of psychiatric prevalence in this population, at least collectively speaking.

Implications for practice, policy, and future research

Severe acute COVID-19 patients experiencing long-term sequelae are a vulnerable population with complex care needs, and this study’s findings suggest that clinicians and policymakers should consider this groups’ long-term psychological health. Providers that deliver continual and holistic care such as GPs are likely well suited to this task²⁶. Whilst the mixed evidence in the literature regarding psychiatric risk factors for affected patients to date makes it difficult to identify individuals with an increased chance of experiencing long-term mental health issues, we contend that there is sufficient evidence to suggest that close attention should be paid to the needs of patients who have pre-existing mental health difficulties and those who experienced severe forms of acute COVID-19.

As for future research, larger scale studies with sample sizes akin to Al-Aly et al.⁴⁸, Chevinsky et al.⁴⁹, Daugherty et al.⁵⁰, and Taquet et al.¹⁵ should be conducted with lengthier follow-up periods, as studies of this nature have the greatest potential to determine the long-term burden of psychiatric issues in affected populations. This study’s findings also suggest that the impact of studies like this would be enhanced by continuing to include robust comparison of enduring outcomes for severe, mild, and moderate acute COVID-19 patients, as well as controls. Comparisons of behavioural outcomes such as alcohol/substance use in study populations should also be examined.