Psychometric properties of the Persian version of the Adult Executive Functioning Inventory

The research, literature, and knowledge base in the area of executive functions increased dramatically in the past 20 years. Executive functions are popular or, in modern parlance, “trending” in the fields of cognitive psychology, neuropsychology, school psychology, and school/pediatric neuropsychology. In the popular press, executive functions are often referred to as the “brain boss” that guides all behavior; and basic definitions of executive functions often associate the frontal lobes as the primary source of these functions. Currently, the Integrated SNP/CHC Model (1, 12, 13) conceptualizes executive functions as independent but moderately correlated constructs and categorizes cognitive flexibility, concept recognition and generation, inhibition, planning, reasoning, and problem-solvingas executive functions. Miller views other common elements of executive functions, such as attention, working memory, and processing speed, as separate neurocognitive constructs that serve as facilitators/inhibitors of higher-order complex processes.Severalnew assessment measures (direct and indirect, targeted, or as part of larger batteries, measuring behavioral or cognitive manifestations) have been published or are in the development phase thatintended to more specifically measure executive functions and differentiate such skills from other neurocognitive constructs. Moreover, unlike other ratings of executive functioning, such as the BRIEF-A and the BDEFS (75 and 89 items), the ADEXI is a brief instrument comprising only 14 items. Its briefness makes it a suitable tool for evaluation in contexts where time is limited. In this sense, it could be used as a complement in the EF assessment of a wide range of patients, and it could also be combined with the use of laboratory measures, as has been suggested, given the low correlation between the two types of measures in specific populations. Likewise, briefness is an additional asset in the clinical field, considering that subjects' executive problems may struggle to compelete longer instruments, given their difficulty stayingfocused. The Adult Executive Functioning Inventory (ADEXI) seeks to assess EF by considering these limitations. The present study aimed to analyze the factor structure, the convergent and divergent validity, and the reliability of a Persian adaptation of the ADEXI in a non-clinical population.

Participants were 250 typically developing adults between 18 and 60 years old. Inclusion criteria were: age 18-60 years; fluency speaks in the Persian language; being able to provide informed consent to participate in the study; no history of neurodevelopmental, psychological, and a history of severe head injury or brain injury and other medical conditions that better justify cognitive impairment in participants. Furthermore, participants who unanswered 10% or more of the questionnaire were excluded from the study. Measures The Adult Executive Functioning Inventory (ADEXI): The ADEXI Holst and Thorell is a brief EF inventory, with only 14 items, scored on a likert-like scale of 5 points, from 1, “It does not describe me”, to 5, “It describes me very well”. It is suitable for evaluatingthe adult population with no clinical disorders since it does not describe extreme or pathologic behaviors, and it assesses two specific EF dimensions: Inhibition and working memory (25). The authors also found a high internal consistency for the ADEXI full scale, both for the inhibition and working memory dimensions and an adequate test-retest reliability, with estimates ranging between 0.68 and 0.72 for bivariate Pearson correlations (25).Behavior Rating Inventory of Executive Function–adult version (BRIEF-A): The BRIEF-A Roth et al. (24) consists of 75 items, each with three response choices: “never”, “sometimes”, or “often”. This measure is composed of an overall score (GEC) and two indexes, the MI and BRI. The BRI consists of four scales (Inhibit, Shift, Emotional Control, and Self Monitor) and MI includes five scales (Initiate, Working Memory, Plan/Organize, Task Monitor, and Organization of Materials). In the normative sample,moderate to high internal consistency has been reported for the scales (α=0.73-0.90), as well as for the indices and the GEC (α=0.93-0.96) (24).Persian version of the ADEXI: A Persian version of the ADEXI was derived from the English version of the ADEXI (25), based on standard translation guidelines and cultural adaptation processes, while observing applicable standards for educational and psychological testing (e.g., 28). First, the ADEXI was translated into Persian by two bilingual experts fluent in both Persian and English. As an additional check, a native English speaker, who was also fluent in Persian, was asked to translate the Persian version into English, and this reversed translationwas assessed for any discrepancies by two cognitive psychologists. Once the Persian version of the ADEXI progressed through the checks as mentioned earlier, pilot testing was performed with 20 adults; they were also asked to provide feedback on the clarity and comprehensibility of the questionnaire. Once the concerns highlighted in the pilot were fully addressed, the final Persian version of the ADEXI was used for the complete psychometric testing on250 adults reported herein. Participants answered all ITQ-CA items on a 5-point likert scale ranging from 1, “It does not describe me”, to 5, “It describes me very well”.Analysis Plan To describe demographic variables and obtain descriptive statistics of the items, IBM SPSS-28 was used, and Mplus version 8.3.2 with Maximum Likelihood Robust (MLR) estimation was used to carry out the CFA of the model.

Regarding demographic data, most of the participants were young adults (M=28.76; SD=5.09) years. Among the participants in the present study, 124 were male (49.6%), and 126 were female (50.4%). The educational level of the sample indicated that 98 (39.2%) had diplomas and lower, 87 (31.2%) had bachelor's degrees, and 65 (26%) had master's and doctoral degrees. In addition, 165 (66%) of the participants were married, and 85 (34%) were single. Findings indicated that the Persian version of the ADEXI form yielded scores with robust reliability (internal consistency ranging from 0.82 to 0.85 and test-retest correlations ranging from 0.89 to 0.90). Moreover, adequate convergent validity (correlations with the BRIEF-A ranging from 0.63 to 0.68). With respect factorial validity, and SEM revealed that a two-factor solution was the best fitting model for the Persian ADEXI. We evaluated measurement fit using the following fit indices and respective thresholds for fit: CMIN/df<5; Comparative Fit Index (CFI)>0.90; Root Mean Squared Error of Approximation (RMSEA)<0.08; Standardized Root Mean Square Residual (SRMR)<0.08; Tucker Lewis Index (TLI)>0.90 (32). The results from the measurement fit indices were favorable and highlighted that the ADEXI fit the data adequately (Table 1).

Conclusively, the ADEXI can be a valuable screening instrument for assessing deficits in working memory and inhibitory control in Iranian adults. However, similarly to other EF ratings, the ADEXI should be used as a complement rather than a replacement for neuropsychological tests. Taken together, the present study's results indicate that the Iranian adaptation of the ADEXI shows satisfactory psychometric properties and would be a valid and reliable measure to assess EF. Executive function behavioral rating scales are valuable tools to generate hypotheses about potential executive function deficits that should be further validated with actual performance on tests of executive functioning. Under no circumstances should a behavioral executive function rating scale be used as the sole measure of executive functioning.