In the last 2 years, the increase in COVID-19-related deaths has become the greatest threat to human health in the current century (Plohl and Musil, 2020); By November 26, 2021, 5,174,646 million people worldwide have lost their lives. By the widespread outbreak of the SARS CoV-2 virus, World Health Organization [WHO], 2020 has declared a public health emergency worldwide (Afrashteh et al., 2020).

The high prevalence of COVID-19 has negatively affected individuals and communities’ physical, social, psychological, and mental functioning which has had significant economic, social, and health consequences (Algahtani et al., 2021). Besides, it has led to increased psychosocial and physical stress such as fear of infection and death, the spread of fake news and rumors, interference in activities of daily living, travel bans and restrictions, social isolation in terms of quarantine or other distancing measures, and occupational and financial problems (Alipour et al., 2020). In this respect, the findings of Wang et al. (2021) demonstrate that COVID-19 has moderate to severe psychological effects that might cause feelings of anxiety, depression, and fear in people. Godinic et al.’s research looks at the effects of the COVID-19-related economic crisis on people’s mental and psychological health (Godinic et al., 2020; Ganesan et al., 2021). The unique nature of COVID-19, the need to maintain public safety, social distancing, limited educational and care resources, prolonged illness duration, inadequate knowledge about providing care and being an emerging disease, along with physical problems resulting from the disease might have led to increased isolation and solitude and intensified psychological stress in these patients (Holt-Lunstad et al., 2015). Moreover, compared to other patients, caring for these patients has posed additional challenges to family caregivers (Mirzaei et al., 2020). By managing care, creating proper communication, and educating patients, family caregivers assist minimize psychological and health stresses on the country’s health system and empower people to cope with disease (Dixe et al., 2019). These caregivers are often affected by the biological and physiological damage caused by the patient care process, and they are likely to experience reduced social activities, lack of leisure time, and reduced relationships with family and friends (Magliano et al., 2005). In addition to the caring role, most family caregivers are confronted with other challenges such as job management, housekeeping, childcare, concerns about their children’s education due to school closures, new economic pressures, high medical costs (Kent et al., 2020), and protecting self and family members against virus spread, all of which affect their quality of life (Dinç and Erdoğan, 2021).

Quality of life is an important measure of a society’s health and well-being, and its assessment may lead to the identification of a broad variety of issues that influence people’s everyday lives. World Health Organization defines the quality of life as an individual’s mental perception of the impact of illness or medical condition on various domains of life, including physical, mental, social, and occupational functioning (Algahtani et al., 2021). COVID-19 pandemic has negatively affected the quality of life of all strata of society, especially family caregivers (Dinç and Erdoğan, 2021). During a pandemic, support systems for family caregivers are essential to enable them to efficiently cope with spiritual and physical problems (Dinç and Erdoğan, 2021).

Therefore, it is necessary to measure family caregivers’ quality of life using reliable tools to develop and provide the most efficient services (Axelsson et al., 2020). Quality of Life in Life-Threatening Illness–Family Carer Version was designed by Cohen et al. (2006) in English and French. Its validity and reliability were confirmed. This scale measures caregivers’ quality of life and their perception of the patient’s life-threatening and challenging condition (Cohen et al., 2006). The instrument has been translated, and its psychometric properties were investigated in various cultures, including Australian (Bradford et al., 2012), Swedish (Axelsson et al., 2020), German (Schur et al., 2014), Spanish (Arias-Rojas et al., 2021), Malaysian (Alnjadat et al., 2014), Indian (Nayak et al., 2014), and Czech (Bužngová et al., 2015). However, a Persian tool to measure family caregivers’ quality of life in Life-threatening illnesses has not been designed or psychometrically investigated. Therefore, this study aimed to translate and determine the psychometric properties of the Persian version of the Quality of Life in Life-Threatening Illness–Family Carer Version in the families of patients with COVID-19 (QOLLTI – F).

During COVID-19 pandemic, family caregivers’ quality of life was severely affected. Family caregivers provide measures associated with the symptom management, treatment, and the patient’s physical, psychological, and social care (Arias-Rojas et al., 2021). Therefore, addressing caregivers’ problems is essential to provide appropriate treatment and social support to patients and ensure the continuity of care (Karimirad et al., 2018). Consequently, QOLLTI-F is a valid tool to assess family caregivers’ quality of life. The present study was conducted to investigate the psychometric properties of the Persian version of the QOLLTI – F.

This study discreetly performed the translation process until a final Iranian version was obtained. Similar to the results of this study, the face validity of the original English version of scale was assessed by Cohen et al. with a sample size equal to 30 caregivers (Cohen et al., 2006). In addition, face validity was assessed in the German version (Schur et al., 2014) by 30 caregivers, the Latin American–Spanish version (Arias-Rojas et al., 2021) by 21 caregivers, the Swedish version (Axelsson et al., 2020) by 15 patients and nine caregivers, and in the Malaysian version (Alnjadat et al., 2014) by 10 caregivers, which indicated that the items were straightforward and clear after being translated.

The present study used EFA, CFA, and convergent validation to confirm the construct validity using the ZBI. Regarding the number of extracted factors (3 factors) following EFA, the present study is consistent with Arias-Rojas et al.’s study (Arias-Rojas et al., 2021), conducted to prepare the American–Spanish version. However, the result of EFA in this study was inconsistent with the study by Schur et al. (2014) to develop the German version (4 factors extracted), the study by Alnjadat et al. (2014) in preparing the Malaysian version (7 factors extracted), and the study by Cohen et al. (2006) to prepare the original version of the scale (7 factors extracted). This difference is probably due to the disease nature in the studied populations and sample size. In contrast to the present study, in the studies by Alnjadat et al. (2014) and Schur et al. (2014), no CFA was performed; however, the researchers in this field recommend performing this stage of construct validity in future studies.

Pearson correlation between two scales (QOLLTI-F-V3 scale and the ZBI) indicated an appropriate correlation and confirmed the convergence validity of this scale. In other words, the higher the burden of care, the lower family caregivers’ quality of life will be.

Similar to the present study, in the study by Schur et al. (2014) the Integrative Hope Scale (IHS) was used to assess concurrent validity. Besides, the Hospital Anxiety and Depression Scale (HADS) and the Subjective Carers Burden questionnaire were used to assess discriminant validity, revealing a significant relationship between the two scales.

The present study indicated the appropriate reliability (Cronbach’s alpha and Test-retest) of the scale. This result was in line with the results of the original version of the QOLLTI-F scale with reliability (Cronbach’s alpha = 0.86) and stability (Test-retest = 50–0.79) (Cohen et al., 2006). Furthermore, the results of the present study regarding reliability were in agreement with the results of the study conducted by Schur et al. (2014) to localize the German version (Cronbach’s alpha = 0.83) and stability (Test-retest = 0.92) (Schur et al., 2014), the study by Alnjadat et al. (2014) to localize the Malaysian version (Cronbach’s alpha ≥ 0.74), and the study by Arias-Rojas et al. (2021) to localize the Latin American–Spanish version of QOLLTI-F scale (Cronbach’s alpha = 0.83) and stability (Test-retest = 0.87).

To conclude, according to the psychometric properties of tool in the Persian version, it can be stated that it is an excellent scale to be used to measure family caregivers’ quality of life. Another advantage of the tool is its conciseness, which requires ten minutes to complete. This tool was widely validated, and its different versions are available in various languages.

QOLLTI – F is a valid and reliable questionnaire to measure the family caregiver’s quality of life during a life-threatening illness. Therefore, it can be used in clinical evaluation and research to improve family caregivers’ quality of life in Iranian society. This tool can be used in various diseases and medical centers, including hospitals, nursing homes, and hospice centers.

The original contributions presented in the study are included in the article/supplementary material, further inquiries can be directed to the corresponding author.

AF: conceptualization, methodology, draft preparation, and data collection. AE and MR: methodology and draft preparation. SH: methodology and draft preparation. MM: supervision, data collection and draft preparation. AK, MJ, BA, and MSR: data collection and draft preparation. SB: supervision, conceptualization, methodology, draft preparation and data collection. All authors contributed to the article and approved the submitted version.

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

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