Validity and Reliability of the Persian PHQ-9 in Community-Dwelling Adults

Abstract

Introduction

Depression is one of the most common mental disorders worldwide and in Iran. Although the PHQ-9 has been translated into Persian, the previous Iranian validation was conducted in psychiatric outpatients with a relatively small sample and did not fully examine its performance in the general population. Therefore, further evaluation of the Persian PHQ-9 in a community sample was needed.

Method

This cross-sectional study used a convenience sampling method to employ 1169 participants from public locations in Gonabad, Iran, between 2024 and 2025. Eligible participants were adult residents (aged 18 years or older) who could complete the questionnaires in Persian. After completing the questionnaires in a self-report manner, Cronbach’s alpha, McDonald’s omega, and Intraclass Correlation Coefficient (ICC) indices were calculated to assess reliability. Also, to assessed the construct validity, confirmatory factor analysis (CFA) and exploratory factor analysis (EFA) was carried out.

Results

A total of 1,169 participants were included in the analysis. In the EFA subsample, the mean age was 37.66 ± 13.50 years, and in the CFA subsample, it was 36.26 ± 12.94 years. The one-factor model showed acceptable fit indices in CFA (CFI = 0.945, RMSEA = 0.078, AGFI = 0.924). Cronbach’s alpha, McDonald’s omega, and the ICC were 0.863, 0.869, and 0.932, respectively. The final model was unidimensional with one correlated residual. In reliability stage, Cronbach’s alpha, McDonald’s omega, and ICC for PHQ-9 were 0.863, 0.869 and 0.932 respectively.

Conclusion

The results of this study confirm that the Persian PHQ-9 is an appropriate and brief instrument for assessing depression severity in the Iranian population.

Introduction

Depression ranks among the most prevalent mental health disorders globally, as well as within Iran.^1,2 Prior to the onset of the COVID-19 pandemic, approximately 322 million people worldwide were affected by depression, with an estimated prevalence of 15 to 20 percent within the Iranian population.^2,3 However, the onset of the COVID-19 pandemic precipitated a 25 percent surge in the global prevalence of depression. ⁴ Depression is widely regarded as one of the most debilitating mental disorders and constitutes a leading contributor to the global burden of disease. ⁵ Persistent depressive mood, along with disturbances in appetite and sleep, a marked loss of interest in daily activities, and suicidal behaviors, constitute the core symptomatology of depression. ⁶ Depression can affect biological functioning by altering sleep, appetite, energy regulation, and stress-related physiological processes, and it may contribute to impaired daily functioning and reduced quality of life.

The early diagnosis and timely administration of appropriate treatment for depression represent essential public health priorities. ⁷ However, a significant unmet need for effective screening and diagnosis persists, leading to inadequate treatment of this disorder. ⁸ On average, over fifty percent of depression cases remain undiagnosed in primary care settings and, consequently, do not receive appropriate treatment. ⁹ Consequently, the American Psychiatric Association guidelines emphasize the critical importance of comprehensive diagnosis and assessment prior to initiating any treatment regimen. ⁹

There is an urgent need for an appropriate tool for early diagnosis of depression. ¹⁰ As a result, the development and psychometric testing of specific tools can be the first step towards diagnosing this disorder. ⁷ Among the instruments developed for this purpose, the Beck scales, particularly the Beck Depression Inventory (BDI), are prominent examples. The Beck Depression Inventory (BDI), created in 1961, is a 21-question test that measures depression severity on a 0-3 scale per question. ¹¹ The Depression, Anxiety, and Stress Scale (DASS) is a later tool, introduced in 1995. It has two formats: a full 42-item version and a shorter 21-item version. ¹² This questionnaire measures symptoms of depression, anxiety, and stress from the past week. ¹³

Compared to existing instruments, the Patient Health Questionnaire-9 (PHQ-9) is also short, versatile, and easy to score, which measures depressive symptoms and their severity according to Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV). This instrument has been translated into more than 80 languages, a fact that attests to its widespread international acceptance and utility.^14,15 Although the PHQ-9 was translated and psychometrically validated for use in Iran by Dadfar et al, the study had several limitations. First, it was conducted with a relatively small sample size of 130 participants. Second, the sample consisted solely of psychiatric outpatients rather than being drawn from the general population. Finally, the authors limited their validity assessment to reporting factor loadings and did not provide any measurement model for the instrument in the article. ¹⁶ Although the PHQ-9 has been previously translated and validated in Persian, the earlier Iranian study was conducted among psychiatric outpatients and included only 130 participants. In addition, symptom expression may vary across cultures, particularly for somatic and psychomotor symptoms. For this reason, a community-based validation in an Iranian sample was necessary. Therefore, this study was performed in 2024-2025 with the aim of translating this scale and examining its validity and reliability in the Iranian general population. This study is a Psychometric validation study; therefore, validity, reliability, and factor structure were assessed in accordance with the COSMIN guidelines.

Method

This cross-sectional-psychometric study was performed in 2024-2025 among 1200 participants in the general population of Gonabad city (southern Khorasan Razavi province), Iran, to investigate the psychometric properties of the PHQ-9.

Sample Size

Tabatchnick and Williams recommended that 500 or more sample size enough for performing confirmatory factor analysis.^17,18 Because exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) should ideally be conducted on separate samples, the total sample was divided into two independent subsamples. ¹⁹ A larger sample was selected to ensure stable estimation of factor loadings and model fit indices. So, for performed the EFA and CFA, two separate sample were used and totally 1200 samples selected. The total sample was divided into two independent subsamples for EFA and CFA. The allocation procedure was randomly performed.

Participants and Sampling

Participants were adult residents of Gonabad, Iran, aged 18 years or older who were able to complete the questionnaire in Persian and had lived in Gonabad for at least one year. This criterion was used to ensure that participants were stable community residents and sufficiently familiar with the local context. Individuals with a self-reported history of severe cognitive or neurological disorders were excluded. The questionnaires were completed in a self-report manner. After reviewing the questionnaires, responses with less than 80% completion on the PHQ-9 were excluded from analysis to improve data quality and reduce bias due to missing data. Participants were recruited from public locations in Gonabad, including universities, offices, parks, mosques, clubs, and households, between October 2024 and January 2025. Trained research assistants explained the purpose of the study, obtained informed consent, and asked participants to complete the self-report questionnaires on site.

Tools

Demographic Section

Information such as occupation, marital status, sex, place of residence, age and level of education were collected.

PHQ-9

The PHQ-9 is a 9-item self-report scale designed by Kroenke et al to assess depressive symptoms over the previous two weeks. Each item is rated on a 4-point Likert scale from 0 (“not at all”) to 3 (“nearly every day”), yielding a total score from 0 to 27. Higher scores denoted greater depressive symptom severity. Example items include “little interest or pleasure in doing things” and “feeling down, depressed, or hopeless.” With 9 items, the PHQ-9 measures 9 different symptoms of depression including loss of interest and pleasure, feelings of depression and hopelessness, sleep problems, eating problems, feeling of lack of energy, concentration problems, suicidal thoughts, etc., for major depressive disorder, according to the Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV).^15,20-23 The final Persian version of PHQ-9 was attached (Supp 1).

Translation of PHQ-9

First, written permission was obtained to translate and use the PHQ-9 from original designer.^15,20-23 In this study, the clear and user-friendly guideline presented by Sousa et al, was used. According to this guideline, the steps were 1. translation of the PHQ-9 from English to Persian by two bilingual translators, one of whom was proficient in psychiatric concepts; 2. review of the two translations provided by the two translators, review and discussion of the differences between the two translations, and merging of the two translations by the research team; 3. back translation, that is, from Persian to English by two bilingual translators who were blinded to the original English version; 4. comparison and synthesis of the two English versions by the research team; 5. comparison of the final English version with the original version; 6. translation of the final English version into Persian; 7. pilot study of the translated questionnaire in a small group of the general population (n=10). ²⁴

Assessment of Measurement Properties

Based on the COSMIN guidelines (Supp 2), ²⁵ this study evaluated the following measurement properties of the Persian PHQ-9: face validity, content validity, construct validity (EFA & CFA), and, reliability (McDonald’s Omega, Cronbach’s Alpha, and Intraclass Correlation Coefficient (ICC)).

Pre-Specified Hypotheses

We hypothesized that the Persian PHQ-9 would conform to the original unidimensional factor structure, demonstrating excellent fit indices in both Exploratory and Confirmatory Factor Analyses. Also, we hypothesized that the scale would demonstrate good to excellent reliability, with both Cronbach’s alpha, McDonald’s omega and ICC values exceeding 0.70.

Face and Content Validity

In this study, face validity was assessed in terms of the simplicity of the words and phrases of the items and their comprehensibility by a number of participants and experts. Content validity was also assessed quantitatively by calculating the content validity index (CVI) and content validity ratio (CVR). Content validity was assessed using CVI and CVR. The CVI reflects the relevance of each item, whereas the CVR reflects whether an item is considered necessary by experts. In this study, items meeting the acceptable CVR threshold for eight experts were retained.

In this regard, the translated questionnaire was sent to 8 experts in the fields of psychological sciences, health education and health promotion and they were asked to rate the items in terms of their necessity and relevance. According to the Lawshe table with 8 experts, a cut point of 0.75 was considered for CVR. ²⁶

EFA

In this stage, missing data was checked. Also, Mahalanobis test was employed to determine the outlier data. Finally, skewness and kurtosis were used to data normality. After that, in extraction phase, the extractable factor with eigenvalues more than 1 were assessed by maximum likelihood extraction method.^27,28 Then, KMO (Kaiser Meyer Olkin) was used to checked the adequacy of the sample size. The significance of the Bartlett’s Test of Sphericity) BTS(( BTS< 0.05, 0.8 ≤ KMO ≤ 1) indicates that factor analysis of data can be useful. ²⁹

CFA

In this step, the data related to 601 people were entered into Amos version 24 software after filtering. Initially, skewness and kurtosis were checked and normality was assessed. Mahalanobis test was also used to identify outliers. Next, Maximum likelihood was used to perform CFA and examine the data compliance with the PHQ model. The fit indices used are: Adjusted Goodness of Fit Index (AGFI), Tucker Lewis index (TLI), comparative fix index (CFI), Incremental Fit Index (IFI), Root mean square error of approximation (RMSEA), Relative Fit Index (RFI), Normed Fit Index (NFI), Parsimonious normed fit index (PNFI), Parsimony goodness of fit index (PGFI), Chi-square (χ2), Degree of freedom (df), and goodness-of-fit index (GFI). Acceptable Range: χ2/df < 5, AGFI > 0.9, TLI > 0.9, CFI > 0.9, IFI > 0.9, RMSEA < 0.08, RFI > 0.9, NFI > 0.9, GFI > 0.9. PNFI > 0.5, and PGFI > 0.5.^30-33

Reliability

At this stage, the PHQ-9 questionnaire was evaluated in terms of internal consistency reliability (calculation of McDonald’s Omega by JASP v _0.11.1 software and calculation of Cronbach’s Alpha with SPSS v₂₄ software). In test-retest reliability, 28 participants were assessed two separate occasions (time interval: two weeks). In test–retest reliability, Intraclass Correlation Coefficient (ICC) (Model: two-way mixed, Type: absolute agreement) was calculated with SPSSv₂₄ software.

Statistical Analysis

Descriptive statistics were used to summarize participant characteristics. EFA and CFA were conducted on separate subsamples. We evaluated internal consistency using McDonald’s omega and Cronbach’s alpha, and employed the intraclass correlation coefficient to determine test-retest reliability. Statistical significance was determined based on the conventional cutoff.

Reporting Guideline

This study was conducted and reported in accordance with the relevant EQUATOR reporting guideline for psychometric studies. ³⁴

Ethics Approval and Consent to Participate

This study is based on a research project approved by Ethics Committee of Gonabad University of Medical Sciences with the code of ethics IR.MUMS.REC.1403.260. All procedures performed in this study were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable. Written Informed Consent was obtained from all subjects. Original ethics approval document was attached (Supp 3).

Results

Demographic Characteristics

The response rate was 97 % and totally 1169 samples entered in analysis section (sample size for EFA=568 samples, for CFA=601 samples). The demographic characteristics of the participants are illustrated in Table 1. In the EFA subsample, the mean age was 37.66 ± 13.50 years, and in the CFA subsample, it was 36.26 ± 12.94 years.

Table 1.

Frequency Distribution of Demographic Characteristics

Variables		EFA (n=568)		CFA (n=601)
		n	%	n	%
Sex	Female	312	55.1	365	61
	Male	254	44.9	233	39
Occupation	University student	105	19	118	20.3
	Housewife	155	28.1	194	33.3
	Employed	129	23.4	131	22.5
	Retired	67	12.1	41	7
	Self-employed	96	17.4	98	16.9
Education level	Illiterate	7	1.3	6	1
	Elementary school	13	2.3	21	3.6
	Middle school	26	4.7	25	4.3
	High school	30	5.4	24	4.1
	Diploma	117	21.1	132	22.6
	Associate degree	82	14.8	91	15.6
	Bachelor degree	204	36.7	226	38.6
	Master’s degree or high degree	76	13.7	60	10.2
Marital status	Single	147	26.1	169	28.4
	Married	404	71.9	418	70.3
	Divorce	11	2	8	1.3

Face and Content Validity

In this study, in the qualitative face and content validity evaluation stage, some of the words in the questionnaire items were replaced with simpler equivalents according to the participants and experts. In the quantitative content validity evaluation stage, two S-CVI/Ave and CVR indices were calculated based on the scores of 8 experts, which was 0.94 and 1 for PHQ-9, respectively (Table 2).

Table 2.

The I-CVI and Modified Kappa for Each Item of PHQ-9

Tool	Items	Number of agreement	I-CVI (Item-level content validity index)	Pc (Probability of chance agreement)	K (Modified kappa)	Evaluation	CVR
PHQ-9	1	8	1	0.00390625	1	Valid	1
	2	8	1	0.00390625	1	Valid	1
	3	8	1	0.00390625	1	Valid	1
	4	8	1	0.00390625	1	Valid	1
	5	8	1	0.00390625	1	Valid	1
	6	8	1	0.00390625	1	Valid	1
	7	8	1	0.00390625	1	Valid	1
	8	8	1	0.00390625	1	Valid	0.75
	9	8	1	0.00390625	1	Valid	0.75

EFA of PHQ-9

In EFA stage, normality assessment indicated that data were normal and Missing data could not be found. At this stage, the Kaiser–Meyer–Olkin (KMO) measure was computed, yielding a value of 0.894, which confirms the adequacy of the sampling. Also, results of bartlett’s test approved the sampling adequacy (χ2 = 2108.975, p < 0.001, df = 36). Then, results of extraction (extraction method: maximum likelihood), only showed one factor with eigenvalues more than 1 and explained 45.75% variance of PHQ-9.

CFA of PHQ-9

In the first model of PHQ-9, not used any modification (Figure 1). Because in the first model, some of goodness-of-fit indices were not acceptable. In the second CFA model, a correlated residual was added between items 3 and 5 based on the modification indices and the conceptual similarity of these two somatic items and after that the value of all goodness-of-fit indices were improved (Figure 2 &Table 3), but the chi-square test was significant (p < 0.05), which is common in large samples. In the first and second models, all factors loading of PHQ-9 were more than 0.4 (Figures 1 and 2).

Figure 1.

Standardized parameter estimates for the factor structure of the Persian version of PHQ-9 without any modification

Figure 2.

Standardized parameter estimates for the factor structure of the Persian version of PHQ-9 with one modification (The value shown between e3 and e5 represents the correlated residual covariance added in the revised CFA model)

Table 3.

The Model Fit Indicators of the Persian Version of PHQ-9

Goodness of fit indices	Confirmatory factor analysis of first model without any modification	Confirmatory factor analysis of second model with modification	Acceptable value
X2	139.985	121.777	-
df	27	26	-
X2/df	5.185	4.684	< 5
P-value	0.000	0.000	p > 0.05
CFI	0.936	0.945	> 0.9
RFI	0.896	0.906	> 0.9
GFI	0.950	0.956	> 0.9
AGFI	0.916	0.924	> 0.9
IFI	0.936	0.946	> 0.9
RMSEA	0.084	0.078	<0.08
NFI	0.922	0.932	> 0.9
PNFI	0.691	0.673	> 0.5
PGFI	0.570	0.552	> 0.5
TLI	0.914	0.924	> 0.9

Reliability

The Internal consistency reliability of PHQ-9 was approved and the value of Cronbach’s alpha coefficient was 0.863 and McDonald Omega coefficient was 0.869. Test-retest reliability was assessed in a small subsample of 28 participants because repeated follow-up was limited by time and participant availability. The value of ICC was 0.932 (P-value <0.001, 95% Confidence Interval: Lower Bound= 0.840, Upper Bound=0.970) for PHQ-9.

Discussion

This study aimed to evaluate the psychometric properties of the Patient Health Questionnaire-9 (PHQ-9) within adult community-dwelling residents of Gonabad, Iran. The results of this study showed that the Persian PHQ-9 has acceptable validity and reliability in adult community-dwelling residents of Gonabad, Iran, However, the results should be interpreted with care, given the model adjustments and methodological limitations. Confirmatory factor analysis supported a unidimensional structure, affirming the validity of the single-factor model with its nine items. This finding indicates that the PHQ-9 adequately measures the severity of depressive symptoms, as defined by prevailing clinical standards. Also, the final RMSEA value of 0.078 indicates acceptable fit and should be interpreted together with the other fit indices rather than in isolation.

Based on the findings of the present study, the results are consistent with a psychometric evaluation by Shaff et al, which also demonstrated adequate reliability for the PHQ-9 in a multiracial and multiethnic adult population within the United States. ³⁵ Kroenke et al also showed in a systematic review that the PHQ-9 and its abbreviated versions such as the eight-question version (PHQ-8), the four-question version, and even the two-question version (PHQ-2) had good sensitivity and specificity for diagnosing depressive disorders. ²³

Our findings are consistent with a growing body of international literature that supports the cross-cultural validity of the PHQ-9. For instance, the unidimensional factor structure observed in our study aligns with validations conducted in diverse populations, including in the United States, ³⁵ Germany, ³⁶ and China. ³⁷ The lower factor loadings observed for Items 8 and 9 may demonstrate the more complex or sensitive nature of these symptoms compared with the other PHQ-9 items. It highlights the influence of cultural context on the manifestation and reporting of depressive symptoms. A study validating the Arabic version of the PHQ-9 also reported a slightly lower factor loading for the anhedonia item, ³⁸ suggesting that the conceptualization of pleasure and its expression may vary across cultures. Similarly, studies in other Asian populations, such as in Korea, ³⁹ have discussed the need to carefully interpret psychomotor symptoms due to cultural differences in somatic expression and stigma. This comparative perspective underscores that while the PHQ-9 is a robust tool globally, its application must be sensitive to cultural nuances that can affect the performance of specific items.

The observed lower factor loadings for Items such as 8 (Psychomotor Agitation/Retardation) warrant careful interpretation. Regarding Item 8 (“Moving or speaking so slowly that other people could have noticed? Or the opposite - being so fidgety or restless that you have been moving around a lot more than usual”), its complexity and observational nature are likely contributors to its lower loading. This item is double-barreled, assessing both psychomotor retardation and agitation. In many cultural settings, especially those where stigma around mental illness is high, individuals may be less attuned to or less willing to report objectively observable psychomotor symptoms. They might instead focus on internal experiences like feeling “slowed down” internally without external manifestation, or report associated symptoms like fatigue more readily. ⁴⁰

In the revised model, only one modification has been made between e3 and e5 in order to improve the fit indices of the model. The possible reason for this improvement in the indices can be considered the relative relationship between items 3 and 5, one of which is related to sleep problems and the other to appetite. In fact, both of them somehow constitute two physiological dimensions of depression (shared somatic content such as sleep–energy–appetite).

Reliability was assessed through internal consistency (using McDonald’s omega and Cronbach’s alpha) and test-retest stability (using the intraclass correlation coefficient, ICC) over a two-week interval, which showed that the questionnaire had adequate reliability. This finding also indicates that PHQ-9 has adequate stability over time, which is very important for monitoring changes in mental health status. Similar to the results of this study, the PHQ-9 has shown high internal consistency in various studies, reporting Cronbach’s alphas ranging from 0.86 to 0.93 in different populations. This indicates that the items in the questionnaire consistently measure the same underlying construct of depression.^35,41,42 However, two limitations should be considered when interpreting the ICC values. First, the two-week interval may be too short for some psychological constructs, potentially introducing practice or memory effects. Second, the use of convenience sampling may have led to bias in the stability estimate, as participants who completed both assessments may differ in demographic or motivational characteristics from the broader sample. Notwithstanding these limitations. Although the PHQ-9 had good validity and reliability, some studies have not considered the use of the ninth item to be sufficient to identify individuals at risk of suicidal thoughts and/or behaviors. Therefore, the use of an additional tool to identify people at risk of suicide is recommended. ³⁵ We recommend that healthcare providers using the PHQ-9 in the Iranian context incorporate additional, validated tools for suicide risk assessment. When Item 9 is endorsed, additional evaluation with a brief suicide-specific screener is recommended. Options include the Columbia-Suicide Severity Rating Scale (C-SSRS) ⁴³ or the shorter P4 suicidality screener.

A notable strength of this study is its large sample size, which may facilitate the broader application of these instruments in future research. This feature also minimized measurement bias for the variables in this study. Also, this study was conducted on the general population and these questionnaires can be used in different target groups. One of the limitations of the current study was that the data was gathered in a self-report manner, and as a result, it may have some errors. We acknowledge that the convenience sampling method, recruiting from public places in a single city (Gonabad), may introduce selection bias, thus limiting the generalizability of our prevalence rates to the broader Iranian population. Also, inter-item correlation was not assessed. Also, small test-retest sample was another limitation of this study. Criterion validity was not assessed because no DSM-based diagnostic interview or other gold-standard external criterion was administered. While this approach saved time and resources, the voluntary and easily accessible nature of the participants means the sample may not be fully representative of the broader target population. A notable limitation of this study is that we assessed the validity and reliability of the PHQ-9 strictly as a measurement instrument, not as a screening tool. Consequently, criterion validity against a clinical diagnostic interview was not established. Future studies should specifically investigate the diagnostic accuracy of the PHQ-9, including its sensitivity, specificity, and optimal cut-off points within the target population. The Persian PHQ-9 may be useful in community and primary care settings as a brief screening tool for depressive symptoms. Its simplicity and short administration time make it suitable for initial assessment and for monitoring symptom severity over time, although positive screening results should be followed by clinical evaluation when needed.

Furthermore, while the identified factor structure for the PHQ-9 was stable and consistent with the original model in our sample, the generalizability of the psychometric properties is explicitly limited to similar urban, community-dwelling populations in Iran. Future validation studies in more diverse, representative samples, including rural and clinical settings, are warranted.

Conclusion

The findings of this study demonstrate that the PHQ-9 is a reliable and valid instrument for assessing the core symptoms of depression among the general Iranian population. As brief, self-administered scales are efficient for classification and measurement, the PHQ-9 is recommended as a suitable tool for use in primary and mental health care settings based on the present results. Nevertheless, further research is needed to examine the scale’s validity and reliability across different populations and ethnic and racial subgroups.

Appendix.

Abbreviations

PHQ-9

Patient Health Questionnaire-9

DSM-IV

Diagnostic and Statistical Manual of Mental Disorders

EFA

Exploratory Factor Analysis

CFA

Confirmatory factor analysis

AGFI

Adjusted Goodness of Fit Index

RFI

Relative Fit Index

NFI

Normed Fit Index

GFI

Goodness of fit index

PNFI

Parsimonious normed fit index

IFI

Incremental fit index

PGFI

Parsimony goodness of fit index

RMSEA

Root mean square error of approximation

X2

Chi-square

DF

Degree of freedom

CFI

Comparative fit index

S-CVI/Ave

Scale content validity index averaging

CVR

Content validity ratio

ICC

Intraclass correlation coefficient.

ORCID iDs

Fatemehzahra Naddafi https://orcid.org/0009-0001-7049-1453

Alireza Jafari https://orcid.org/0000-0003-1390-9830

Mahbobeh Nejatian https://orcid.org/0000-0001-8332-3910

Hadi Tehrani https://orcid.org/0000-0001-8747-8717

Ethical Considerations

This study is based on a research project approved by Ethics Committee of Mashhad University of Medical Sciences with the code of ethics IR.MUMS.REC.1403.260. All procedures performed in this study were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable.

Consent to Participate

Written Informed Consent was obtained from all subjects.

Data Availability Statement

All data generated or analysed during this study are included in this published article.*