This was a prospective content validation ²⁹ and feasibility study ^{30, 31} of the SBC-PAS adapted for OA.

An expert panel collaborated in the content validation process of the SBC-PAS. Initially, three bilingual clinicians translated the SBC-PAS. Additionally, four professionals from different disciplines who provide written consent - neurology, neuropsychology, physiotherapy, and geriatrics - with extensive clinical experience in the care and attention of OA assess the content validity of the SBC-PAS. ^{32, 33}

Considering guidelines for test translation and adaptation, we also obtained information about feasibility ^{31, 34} of applying the adapted SBC-PAS to OA. A convenience sample of OA was recruited. Eligibility criteria included providing written consent; being 60 years of age or older; and having no evidence of cognitive impairment: defined as a score >23/30 on the Mini Mental State Examination ³⁵ ; or evident motor impairment: based on self-report and observation ability to walk across a small room without physical assistance. ³⁶

The Schoeder-Block-Campbell Adult Psychiatric Sensory Integration Evaluation (SBC) was developed to evaluate SI in adults with mental health problems. ²⁶ The original structure consisted of three scales: the first considers clinical history, the second describes the side effects of psychiatric medication, and the SBC-PAS for the evaluation of the main sensory integration systems. For this research, we focus on the content adaptation of the SBC-PAS.

The SBC-PAS comprises 25 sections organized in three dimensions: (a) vestibular-proprioceptive; (b) vestibular-visual; and (c) tactile-proprioceptive; which are related to sensory and motor responses necessary for performance in daily life activities such as balance, coordination, and hand functioning. ^{25, 27}

As the SBC-PAS focuses on the tactile dimension, it includes measures such as ‘Grip Strength’, ‘Fine Motor Control’, ‘Diadochokinesis’ and ‘Finger Thumb Opposition’. However, it does not assess other essential components of tactile perception, such as the ability to differentiate size, shape, texture or temperature, qualities necessary for functionality in daily life. To provide a more complete evaluation of the tactile-proprioceptive dimension, we added three sections: (I) Tactile analyzer of the Barcelona test, ³⁷ (II) Tactile temperature, ³⁸ and (III) Stereognosis. ³⁹ The sections included are described in Table 1.

For the adaptation of the SBC-PAS, we considered the following five guidelines of the second edition of the International Test Commission Guidelines for Translating and Adapting Tests. ^{34, 40} (I) Pre-Condition : to verify construct relevance to OA and original property rights; (II) Test development: to verify adaptation quality through an iterative process of independent translations, review by native speakers with clinical experience with OA, linguistic correction, suitability of the adapted version, and pilot testing for OA; (III) Confirmation: assessment of content validity by an expert panel; (IV) Administration: prepare administration materials, conditions and instructions to guide interaction during administration; and (V) Documentation: description of the adaptation process, modifications made and documentation to use the adapted test.

The SBC is not listed in the World Intellectual Property Organization (WIPO) catalogue, ⁴¹ however the manual has a 1978 Copyright © registration (TXU12-812). ⁴² Since 2019, efforts have been made to reach out to the right holders and ask for official permission to translate and adapt the SBC-PAS, but no answer has been obtained. This research focuses on the adaptation of the SBC-PAS into Spanish only for academic and research purposes, without any commercial or profit-making interest, in accordance with the “fair use”, ⁴³ and giving credit to the SBC right holders. This is done considering the interest in scientific progress and the significance of advancing knowledge about SI assessment, its applicability, and its safety for OA.

The SBC manual was transcribed and double-checked for consistency. It was then translated into Spanish by a Master psychologist certified in SI and then revised by a bilingual clinical psychiatrist with a master’s degree in medical sciences. An English language expert with experience in clinical assessment of OA reviewed the translation to ensure semantic equivalence, operational consistency, and the appropriate use of medical terminology.

After provided written consent and through an iterative process ^{34, 40} the expert panel evaluated the linguistic and operational components of the SBC-PAS for OA as part of the content validity process, ³² using the following criteria ⁴⁴ : relevance (Does the item measure the attribute of the specified dimension?); comprehensiveness or scope (Are the instructions for performing the activity clear to the target population?); application pertinence (Is the item appropriate for use with OA?); and additional observations or comments for each task.

Finally, after adjusting and adapting the SBC-PAS, a feasibility study was conducted with five OA ^{31, 45} without evidence of cognitive or motor impairment ⁴⁶ who provided written consent to participate.

The observations of the expert panel were reviewed, categorized, and compared to consider changes or deletion of sections. The percentage of agreement and the Gwet’s AC ₁ concordance index ⁴⁷ was calculated and interpreted according to the observed agreement proposed by Landis & Koch. ⁴⁸

To assess the feasibility of the SBC-PAS, we examined the response of OA during its administration. Observations were recorded in a designated section of the answer sheet to gather information on human, logistical and procedures requirements, as well as potential implementation challenges. Specifically, the analysis focused on the clarity of instructions, the time needed for completion, the appropriateness and safety of tasks for the target population, and any difficulties encountered by participants or evaluators during the process. ^{30, 31}

As a result of the adaptation and content validity process, the modification, replacement and deletion of sections was related to the vestibular and proprioceptive systems. The modified sections were related to changes in positioning and the use of supports to minimize the risk of injury or falls and ensure the safety of the OA by considering tasks more suitable for OA ^{50, 51}

Although the evaluation of balance can provide important information, we decided to eliminate two items from the scale, ‘Rolling’ (rolling on the floor on a soft surface), ⁵² and ‘Seated equilibrium’ (body control and balance), due to the risk associated with its execution. ^{31, 45} However, sections such as ‘Dominance’ or ‘Grip strength’ could be simplified and reduced. It is necessary to highlight that for ‘Dominance’, crossed or mixed laterality is not an unidimensional trait, and the evaluation of visual preference is complemented with the evaluation of eye-foot motor coordination, ⁵³ which gives information of the compensation mechanisms in their laterality ⁵⁴ For ‘Grip Strength’, it was decided to keep the average of three measurements for both hands in order to have a more consistent measurement. ⁵² While the original version of the SBC focused on the assessment of the vestibular and proprioceptive systems, the SBC-PAS adapted for OA expanded the assessment of the tactile system by considering the qualities of shape, texture, size, hardness and temperature. ⁵⁵ The evaluation of the tactile system is very important since these qualities have been related to manipulation and interaction with the environment, ⁵⁶ the ability to identify nociceptive stimuli related to behavioral problems, ⁵⁷ the expression of needs, interpersonal interaction and quality of life of OA with different cognitive functioning conditions, including OA with Alzheimer’s Disease. ⁵⁸

Regarding the feasibility ^{31, 45} it is important to consider that this is a detailed evaluation that requires: at least a rest period, a large space that allows the use and manipulation of the materials, the participation of the evaluator and an assistant. It is important to have training for getting the clinical and technical skills needed to use the evaluation tools properly.

Recent research has found that age-related sensory impairment may accelerate the pathogenesis of major cognitive impairment, the possibility of being a prodromal indicator in Alzheimer’s disease has been mainly pointed out. ⁷ Thus, evaluation and investigation of the brain structures involved in OA sensory functioning and integration is necessary to understand cognitive functioning. ⁶ The subcortical tactile, ⁵⁹ vestibular ^{60, 61} and proprioceptive systems ^{62– 64} support their role in essential functions such as awareness, orientation, balance and body coordination. ⁶⁵ Likewise, evidence on changes in the activity of subcortical structures is consistent as an indicator of risk for major cognitive impairment. ^{60, 61, 66}

This is why the SBC-PAS for OA represents an enhanced neurocognitive assessment tool that allows the evaluation of SI from these three subcortical systems: tactile, vestibular and proprioceptive. To be able to distinguish changes in sensory functioning due to the process of aging, ⁶⁷ or due to major cognitive impairment such as Alzheimer’s disease ^{68, 69} could guide interventions targeted to preserve or address different cognitive functioning conditions ⁷⁰ with non-pharmacological interventions ^{4, 5, 12} more accessible to low-middle income countries. ⁷¹

Evidence of non-pharmacological interventions for OA with major cognitive impairment such as stimulation of sensory systems separately or together such as SI, has been associated with benefits and improvements on passivity, social isolation, physical ⁷² and emotional wellbeing, behavioral agitation, ^{57, 73} disruptive behaviors, ²⁰ in addition to the inherent implications for their care and attention. ^{20, 74} The evidence of interventions developed from SI is consistent on the benefit and improvement on disruptive behaviors, ²⁰ cognitive abilities, self-expression, affect, social awareness, orientation, motor coordination, ¹⁸ independence in self-care tasks, ¹⁹ decreasing dependence, ²⁰ and in the quality of life of OA and their caregivers. ¹⁹

However, since the first SI interventions with OA ^{18, 20} the assessment of intervention effects has been measured based on variables related to improvements in the level of daily functioning (cognitive, behavioral, social and emotional). There is no documented instrument or scale such as the SBC-PAS that we have adapted to assess the behavioral outcome underlying sensory processing at the subcortical level in OA.

Although the SBC-PAS adapted for OA provided evidence of its content validity by an expert panel and feasibility in a group of five OA, it is necessary to expand the evidence with different levels of cognitive functioning. Obtaining these data would allow gathering evidence on its predictive and discriminant validity, as well as strengthening its clinical value and utility. ⁷⁵ Even if the percentage of agreement and concordance index was substantial for relevance and application pertinence, comprehensiveness or scope was moderated. This limitation could be explained by factors related to the assessment and background of experts: tasks evaluated could have biased the perception of the dimension, and knowledge or clinical experience may have influenced the identification of critical aspects. ⁷⁶ Considering a new expert panel evaluation to review this adapted version will allow for a more precise and refined assessment and feedback of its comprehensiveness. ⁷⁷ Likewise, concordance assessment could be more accurate if more clinical experts are included in the expert panel. ^{77, 78}

Among the strengths of this research is that the process for obtaining evidence of adaptation and content validity was rigorous and in accordance with the International Test Commission Guidelines. ³⁴ The results obtained on content validity were moderate to substantial, ⁴⁸ and are supported by a multidisciplinary clinical team specialized in OA and major cognitive impairment, which strengthens its content validity for assessing SI in OA. Another strength is related whit the organization and application format developed for the adapted version which included support images for categorizing response options and coding. ⁴⁵ The final Spanish-adapted version of the SBC-PAS ‘Scoring guide’ for OA was structured in tables to identify and rate each section consistently, reflecting the overall score for each section. In the original version higher score reflects more limited SI so the instructions for the following sections: Diadochokinesis, Thumb Opposition, Upper Extremity Stability, Bilateral Coordination of the Upper Limbs, Line Crossing, and Trunk Stability were reversed to improve its comprehension ⁴⁵ allowing for easier application and registration.

This adaptation opens new possibilities for the evaluation and analysis of the subcortical systems that organize the SI in OA and transcends for those who experience alterations of these structures such as OA with major cognitive impairment. Considering the subcortical systems is a prior step to activating and facilitate cortical processing, ¹⁸ assessing the subcortical systems that organize SI in OA could be useful to identify sensory problems that are associated with cognitive impairment early, as well as to strengthen the design and implementation of accessible non-pharmacological interventions to preserve and promote autonomy, independence and general well-being of OA ⁵ as well as an alternative to improve their care and attention.