Our study involved a large number of patients from Italy who were systematically assessed for neuropsychological signs and symptoms at three timepoints after COVID-19, including a high proportion of patients without previous hospitalization, followed up to more than one year after the acute infection. Patients reported a significantly worse perception of physical and mental health status compared to the Italian normative group, and it remained stable over time, even one year after the acute infection. Other Italian studies assessing HRQoL through the same instruments (SF-36 and EQ-5D), were mainly focused on previously hospitalized patients evaluated not more than six months after COVID-19 [25–29]. One of the key findings of our study was the evidence of a persistent poor health status perception in the post-COVID-19 period. Similarly to previous studies done using SF-36, the most affected domains and the least affected domain were physical role and physical function, respectively [30–32]. When compared to the Italian normative group, both SF-36 (PCS and MCS) and EQ-VAS scores were lower in the study population. Interestingly, these ratings remained stable over the period of observation and, for the mental component of SF-36 and for EQ-VAS, they were even lower at the last evaluations. These findings emphasize that the impact on quality of life in the post-COVID-19 period, is not restricted to the first few months after the acute infection, but it should be considered a concern also at distance. Here, we have analyzed only the first evaluation of the participants, performed during their first referral at our outpatient clinic, even when it occurred several months after the infection, highlighting the necessity of a prolonged follow up. Even though, in this study, details on signs and symptoms of post-COVID-19 syndrome were not reported, the persistence of a poor health status perception could be directly related to the persistence of such symptoms, providing further evidences of the considerable effect of this condition on quality of life.
A recent systematic review [5] reported that the most common factors associated with lower levels of HRQoL, were female sex, older age, the presence of co-morbidities and developing critical illness. Similarly, a previous structured review [7], focusing on the impact of both acute and long COVID-19 on HRQoL, found that age, gender, severity of illness, comorbidity, income and educational level of the patients, were factors related to a worse perception of HRQoL. Our results were partially consistent with these findings. If the association of lower scores in EQ-VAS, MCS and PCS with female gender was strong and clear, the correlation to disease severity was indirect. In fact, a worse perception of HRQoL was observed mainly among patients with comorbidities and patients treated, during the acute phase, with corticosteroids and, only for PCS, immunotherapy. These features may be considered an indirect sign of disease severity, even though the use of noninvasive ventilation was not related to lower scores. Moreover, gender-based inequalities in health and in quality of life, have been frequently documented in several settings [33–35], probably due to the different exposure and vulnerability to specific determinants of health [33], and this phenomenon was particularly evident in the contest of COVID-19, considering that women seemed to suffer more frequently from long COVID symptoms [8, 36] with the consequent impact on the perception of health status and quality of life. As expected, considering the stable scores in SF-36 subscales during the entire period of observation, any association was found between HRQoL and distance from the acute phase. Finally, we did not observe any evidence of association with age, analyzed as a continuous variable, and we did not investigate income and educational level. Surprisingly, our study showed a better perception of MH in patients with previous hospitalization and it could be determined by the fact that patients managed at their own home, experienced the lockdown period and felt worried about the disease progression and potential complications, and insufficiently reassured about the symptoms they experienced. As a result, their perception of these symptoms could be exacerbated and their psychological sphere was possibly affected more the ones hospitalized. On the contrary, the hospitalization could offer more reassurance to the patients by inhibiting their anxious thoughts.
Regarding the presence of anxious-depressive symptoms and sleep disorders, we found that it was associated with a worse perception of health status and QoL. Such correlation is well documented also for other diseases, acute and chronic, and highlights the need to deal with neuropsychiatric symptoms during the post-COVID-19 period [37, 38].
Strengths of the present study were the prospective design and, as already underlined, the large sample size, including patients, with milder forms of COVID-19 and with a long follow up period, systematically evaluated at each visit; moreover, scales and questionnaires were face-to-face administered by health-professionals and neuropsychologists, decreasing the likelihood of misunderstanding and missing responses. The study had also some limitations. First of all, it was a single-center study without a control group of patients; furthermore, the absence of longitudinal data could limit the generalizability of the results; finally, for this analysis, we did not collect details on symptoms and we are aware of the potential selection bias due to the increased willingness of more symptomatic patients to take part in a follow-up study.