The Sensory Processing Dysfunction and Related Postnatal Environmental Factors in Preschool Aged Children in Qingdao, China

Research Article

Austin Orthop. 2016; 1(1): 1002.

The Sensory Processing Dysfunction and Related Postnatal Environmental Factors in Preschool Aged Children in Qingdao, China

Sun Z¹,a, Zhang F²,a, Shi X¹,a, Zhang Q³, Jia X³, Wang B¹* and Gao R¹

¹Qingdao Centers for Disease Control and Prevention, China

²Department of Child Health Care, Maternity and Child Health Care Hospital, China

³Department of Child Health Care, Maternity and Child Care Center of Huangdao District of Qingdao, China

aCo-first authors

*Corresponding author: Bingling Wang, Qingdao Centers for Disease Control and Prevention, No. 175 Shandong Rd. Qingdao 266033, China

Received: March 26, 2016; Accepted: May 04, 2016; Published: May 05, 2016


Previous studies have shown that prenatal chemical or non-chemical exposure may contribute to the Sensory Processing Dysfunction (SPD). To date, few studies have examined the possible influence of postnatal environmental factors on the SPD. We hypothesized that the postnatal environment in early childhood might also influence the SPD. Parents or guardians of pre-school children completed questionnaires about their postnatal living environment. The sensory processing dysfunction profile was used to measure the possible SPD. Results showed girls invulnerable to the SPD in dyspraxia and visual senses with OR (95% CI) 0.42 (0.30, 0.59) and 0.64 (0.48, 0.86), respectively. Strict or let-alone or not special care style seemed averse to the sensory processing compared to generous care style. Lower frequency of floor vacuuming or cleaning indicated higher risk of SPD in vestibular and tactile sensory. Consistently, child with dirty hands usually showed higher risk of SPD in all 6 sensory except proprioceptive senses. Child living in the home having more furniture in bad materials commonly releasing more volatile or semi-volatile organic compounds indicated higher risk of SPD in vestibular or tactile sensory with OR (95% CI) 1.12 (1.00 – 1.24) and 1.16 (1.04 – 1.30), respectively. Poor gestational nutrition, taken drugs during pregnancy, and gestational passive smoking were also entered the multivariate models and showed adverse association. Our results indicate that a social environment of parental guidance and an indoor environment of exposure to chemical are associated with SPD.

Keywords: Postnatal exposure; Environmental exposure; Play behavior; Sensory processing dysfunction; Preschool


The integration of sensory information from the body and the environment is essential for almost every human activity and involves the brain selecting, inhibiting, comparing, and associating sensory information [1]. This information permits the planning and production of organized behavior [2]. The sensory processing patterns could affect the child’s daily experiences, and consequently impact their physical growth, social-emotional development, and academic performance [3]. Therefore, Sensory Processing Disorders (SPD) are regarded as impairments of neurological process of recognizing, modulating, interpreting, and responding to sensory stimulus, and these effects can negatively affect development and functional abilities in behavioral, emotional, motoric, and cognitive domains [4]. The aforementioned problems may affect the child’s performance in school and daily life.

The fetus’ cerebral cortex, one part of the brain which mediates sensory processing, develops during the fetus, and throughout early childhood [5]. The main development period of sensory processing is in preschool childhood ranged from 3 to 6 years, and might contribute to grow after the range of 8 years [6]. Harm to the cortex may negatively impact the ability to sensory integration and other types of information. Previous research has indicated that at least 10- 30% of the total children [7,8] and5-10% of children without other known disabilities [3,4,9]are affected by SPD. Very limited studies on mainland of China has reported that up to 29% of children aged 3-6 years were affected with SPD [10-12], and 21-28% was reported in Taiwan [13]. Although such high prevalence rates have been reported, little is known about the neurobiological substrates of SPD. Prenatal stress and alcohol consumption have been reported as the possible contributors of SPD through alterations in the functioning of the dopaminergic regulatory systems [14]. Some reports indicated that gestation, birth/delivery, and neonatal status were also the strong predictors of future sensory problems [15,16]. The effects of physical contact in the early childhood were also investigated. The studies from Eastern Europe and the United States investigated the effects of the length of the institutionalization of the adopted children on the sensory processing, and found that longer time of institution indicated more sensory processing problems, which suggests that poor environment, low contact, poor nutrition, and abuse may exacerbate sensory processing problems [17,18].

In this study, we collected information about the child’s living environment from the child’s parents or guardians to examine the association of the postnatal environment with sensory processing patterns in kindergarten children.


Participants and recruitment

Four kindergartens were randomly sampled from 11 public kindergartens of a district of Qingdao, China. A total of 2,080 questionnaires were distributed in these four kindergartens, and 1,731 were returned. Of these, 200 questionnaires were excluded because they had insufficient information on the SPD scores. Given that presence and sex of siblings in the home might be the import confounder of the play behavior [19], 192 children from a single-child family were excluded. This left 1,339 participants for inclusion in the analyses.


A questionnaire was tested with the parents of 100 children in one public kindergarten of the sampled district. The questions were rearranged or changed as needed, based on the pilot data. This was done to ensure that the questionnaire was intelligible to parents. The final questionnaire was taken back home by the children, and the guardians who had lived with the children for at least the past 3 months and knew their health condition and day-to-day behaviors were requested to complete the questionnaire, with reference to the parents if necessary.

The questionnaire included 9 parts: 1) general information about their child, 2) gestational information, 3) the family care environment, 4) the indoor environment of the home, 5) the outside environment of the home, 6) the indoor environment of the kindergarten, 7) the disease history of the child, and 8) the severity of the SPD. Most of these questions were based on the “Questionnaire for national investigation for Sick Building Syndrome and its potential risk factors in Japan” [20,21]. The questions about gestation, asked about drugs taken, passive smoking, and nutrition during pregnancy, as well as the mode of delivery. The family-care environment included the educational levels of the guardian, mother, and father, the care style of the parents, the child’s communication time with parents or guardian, and the closeness of the relationship between the child and parents or guardian. Information about the indoor environment of the home included the decorative materials, the nature of the furniture, the ventilation, smoking behavior within the dwelling, frequency of cleaning the floor by vacuuming or other methods, and indicators of dampness (e.g., the presence of dew condensation, mold growth, or water stains) [22]. Given that some semi-volatile organic compounds are released from domestic electric appliances, the number of electric appliances was recorded. Questions about the outside environment mainly concerned exposure to pollutants, including whether the house was near a major street or other known pollution sources. Information about plastic and other chemical odors, uncomfortable feeling or symptoms, and educational mode in the kindergarten were collected. Disease history included any history of allergies, Multiple Chemical Sensitivity (MCS), and newborn diseases, including kernicterus, meningitis, malnutrition, asphyxia, and hypoglycemia, which might influence the development of the nervous system. Other disease-related information included major injuries, such as fractures, infantile convulsions, brain traumas, wheezing, coughing for a long period, frequently catching colds, and frequently taking antibiotics. For the MCS, each child gained one point on the MCS score by setting scale scores to all subjective complaints [23]. Pollution sources near the house were identified as gas station, factory, household waste incineration plant, and other facilities that could cause environmentally related complaints.

The SPD profile is a 60-item guardian questionnaire designed to provide information about the child’s ability to process sensory information. The SPD profile was first translated and standardized by the Institute of Mental Health, Beijing Medical University [24]. After several revised versions, now it consists of 6 subtypes of senses: vestibular (10 items), under-responsively (10 items), tactile (14 items), dyspraxia (11 items), visual (5 items) and proprioceptive (10 items) [25]. Responses to the items of the SPD profile correspond to relative frequency of the occurrence of the child’s behavior, according to the guardian. The answer to each item is reported on a 5-point, Likerttype scale, ranging from never (scored as 1) to always (scored as 5).

Statistical analysis

The raw subtype scores of the SPD profile were transformed into T standard scores. Therefore, higher scores are indicating more typical behavior, whereas lower scores indicate a difference in behavior compared to children without dysfunction.

Given the different sensory processing between the sub-unit senses, subtype SPD prevalence, not the total SPD prevalence, was used for the analysis. Descriptive and summary statistics for relevant variables were examined first, and then bivariate associations were tested. The Kolmogorov–Smirnov test showed that the sub-unit sensory scores were distributed abnormally. Therefore, Spearman’s rho correlations were performed on the continuous variables to test their possible associations with SP scores. The standardized SP scores of the sub-unit sensory were categorized into SPD (≤40) or non- SPD (>40). Then, odd ratio (OR) and 95% Confidential Interval (CI) were calculated by Chi square test to indicate the possible association between categorical variables and the SPD. Both continuous variables in the Spearman’s rho correlation test and the categorical variables in the Chi square test with P<0.05 were tested the co-linearity by a lasso model tuned by cross-validation. Finally, multivariate logistic regression analysis was performed to examine the association between possible risk factors and the SPD. All independent variables were entered into the models backwards; the p-value for inclusion was 0.05 and the p-value for removal was 0.10. A p< 0.05 was considered to be statistically significant. All analyses were performed using IBM SPSS Statistics version 21 (IBM Corp, Somers, NY). The results of the regression analyses for the association between the possible risk factors and the SPD are presented as adjusted OR, together with their 95% Confidence Intervals (CIs) and Wald p-values.


Of all participants, 47.5% were girls and 52.5% were boys. The average age was 4.8 years with the range from 2 to 7 years. About 23.7% subjects were suffered from under-responsive senses, followed by visual, vestibular, dyspraxia, tactile, and proprioceptive senses with 16.3%, 12.8%, 11.9%, 11.7% and 11.7%, respectively (Table 1).