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1.
Psychophysiology ; 59(12): e14117, 2022 12.
Article in English | MEDLINE | ID: mdl-35687668

ABSTRACT

Specific phobia can be treated successfully with exposure therapy. Although exposure therapy has strong effects on self-reported ratings and behavioral avoidance, effects on measures derived from electroencephalography (EEG) are scant and unclear. To fill this gap, spider-phobic individuals received either in-vivo or virtual reality exposure treatment. Patients were tested twice (one week before and after treatment), and control subjects once. In each session, EEG was recorded to spider pictures as well as other positive, negative, and neutral pictures. During EEG recording, participants performed a simple detection task while task-irrelevant pictures were shown in the background. The task was used to reduce potential confounding effects from shifts of attention. After the task, subjects were shown the pictures again and rated each in terms of their emotional reaction (arousal and pleasantness). The results showed that before treatment, patients rated spiders as more negative than did control subjects. Patients also showed elevated early posterior negativity (EPN) and late positive potential (LPP) to spiders. After treatment, the negative emotional ratings of spiders were substantially reduced. Critically, Bayesian analyses suggested that EPN and LPP were unaffected by treatment and that the treatment groups did not differ in their responses (EPN, LPP, and ratings). These findings suggest that the effects of in vivo and virtual reality exposure therapy are similar and that the initial stages of motivated attention (EPN and LPP) are unaffected by treatment.


Subject(s)
Phobic Disorders , Spiders , Virtual Reality Exposure Therapy , Animals , Virtual Reality Exposure Therapy/methods , Photic Stimulation , Bayes Theorem , Phobic Disorders/therapy , Phobic Disorders/psychology , Electroencephalography
2.
Front Psychiatry ; 12: 645273, 2021.
Article in English | MEDLINE | ID: mdl-34093267

ABSTRACT

Consumer Virtual Reality (VR) technology offers a powerful, immersive medium for scalable dissemination of mental health interventions. Decades of research has shown VR exposure therapy to be efficacious in the treatment of anxiety disorders and that the fear reduction generalizes to real-world stimuli. Many studies also report continued improvement over time, after discontinuing VR use. The lowered threshold hypothesis states that this continued improvement is moderated by lowering the threshold to conduct subsequent in-vivo exposure. The current study is the first to formally test this hypothesis, using data from a recent trial on automated VR exposure therapy for spider phobia, in which participants (n = 49) were followed for 1 year, completing assessments 1 week, 3 and 12 months post-treatment. The assessment included validated self-report of phobia symptoms, a standardized behavioral approach test featuring a real spider, and a questionnaire for self-reporting frequency of in-vivo exposures since last assessment. Number of in-vivo exposures was found to be independently associated with greater symptom decrease in longitudinal outcome models. In sequential structural equation models, immediate post-treatment symptom reduction was associated with subsequent in-vivo exposures, which in turn was associated with continued symptom reduction. However, this applied only to self-reported phobia symptoms (not behavioral avoidance) and no associations were found past 3 months. Our findings offer preliminary, partial support for the lowered threshold hypothesis, suggesting that VR exposure interventions may benefit from including explicit in-virtuo to in-vivo transitioning components.

3.
Internet Interv ; 24: 100370, 2021 Apr.
Article in English | MEDLINE | ID: mdl-33665136

ABSTRACT

The advent of affordable Virtual Reality (VR) technology has spurred consumer and commercial interest in VR relaxation applications, which has quickly grown into a popular non-gaming genre on digital marketplaces. While laboratory studies have demonstrated efficacy of VR relaxation for mental health purposes, little is known about how users experience this type of intervention and no study has examined the reception of consumer versions among regular users in everyday life. Studying published user reviews offers a unique window into naturalistic user experiences that complements traditional qualitative methods by circumventing the sampling bias of interview studies, and allowing analyses on full samples, unconstrained by coding resources. Using an innovative, semi-automated Natural Language Processing technique, the current study analyzed 1379 published reviews (including star ratings) of 30 different VR relaxation applications available for the Oculus Go and Gear VR. The uncovered topic structure and sentiment analysis thereof suggests that users have an overall positive view of VR relaxation applications, describing them as successful in inducing immersion and relaxation, and having appreciated gamification elements. However, perceived quality varied substantially between applications that explained more variance in star ratings than specific features. Critical issues raised were both technical (e.g. "overheating") in nature and related to specific design elements and use. Implications for the design of consumer VR applications and future research are discussed.

4.
Cogn Behav Ther ; 50(1): 67-87, 2021 01.
Article in English | MEDLINE | ID: mdl-32870126

ABSTRACT

Virtual Reality (VR) can be used as a therapeutic tool to conduct efficacious in-session exposure therapy by presenting virtual equivalents of phobic stimuli, yet past hardware restrictions hindered implementation in routine care and effectiveness studies. The current study examines the effectiveness of a VR-assisted treatment protocol for public speaking anxiety with demonstrated efficacy, this time in routine care, using affordable VR hardware. Participants (n = 23) were recruited via a private clinic and treated by one of four psychologists with only minimal VR-training. Using a single-subject design and dual-slope modeling (adjusting the treatment-onset slope for treatment effects), we found a significant, large decrease in self-rated public speaking anxiety following the primary three-hour session, similar in magnitude to the previous efficacy trial. Multilevel modeling of in-session process measures suggests that the protocol works as intended, by decreasing catastrophic belief expectancy and distress, and increasing perceived performance quality. Adherence to the online transition program that followed-encouraging in-vivo exposure-was relatively poor, yet symptoms decrease continued. No change was observed over the three-month follow-up period. We conclude that VR exposure therapy can be effective under routine care conditions and is an attractive approach for future, large-scale implementation and effectiveness trials.


Subject(s)
Anxiety/therapy , Speech , Virtual Reality Exposure Therapy , Adult , Female , Humans , Male , Middle Aged , Treatment Outcome
5.
JMIR Serious Games ; 8(2): e17807, 2020 Apr 29.
Article in English | MEDLINE | ID: mdl-32347803

ABSTRACT

BACKGROUND: Virtual reality exposure therapy is an efficacious treatment of anxiety disorders, and recent research suggests that such treatments can be automated, relying on gamification elements instead of a real-life therapist directing treatment. Such automated, gamified treatments could be disseminated without restrictions, helping to close the treatment gap for anxiety disorders. Despite initial findings suggesting high efficacy, very is little is known about how users experience this type of intervention. OBJECTIVE: The aim of this study was to examine user experiences of automated, gamified virtual reality exposure therapy using in-depth qualitative methods. METHODS: Seven participants were recruited from a parallel clinical trial comparing automated, gamified virtual reality exposure therapy for spider phobia against an in vivo exposure equivalent. Participants received the same virtual reality treatment as in the trial and completed a semistructured interview afterward. The transcribed material was analyzed using thematic analysis. RESULTS: Many of the uncovered themes pertained directly or indirectly to a sense of presence in the virtual environment, both positive and negative. The automated format was perceived as natural and the gamification elements appear to have been successful in framing the experience not as psychotherapy devoid of a therapist but rather as a serious game with a psychotherapeutic goal. CONCLUSIONS: Automated, gamified virtual reality exposure therapy appears to be an appealing treatment modality and to work by the intended mechanisms. Findings from the current study may guide the next generation of interventions and inform dissemination efforts and future qualitative research into user experiences.

6.
J Med Internet Res ; 22(3): e16660, 2020 03 24.
Article in English | MEDLINE | ID: mdl-32207690

ABSTRACT

BACKGROUND: Automated virtual reality exposure therapies (VRETs) are self-help treatments conducted by oneself and supported by a virtual therapist embodied visually and/or with audio feedback. This simulates many of the nonspecific relational elements and common factors present in face-to-face therapy and may be a means of improving adherence to and efficacy of self-guided treatments. However, little is known about alliance toward the virtual therapist, despite alliance being an important predictor of treatment outcome. OBJECTIVE: In this study, we aimed to evaluate the first alliance instrument developed for use with embodied virtual therapists in an automated treatment format-the Virtual Therapist Alliance Scale (VTAS)-by (1) assessing its psychometric properties, (2) verifying the dimensionality of the scale, and (3) determining the predictive ability of the scale with treatment outcome. METHODS: A psychometric evaluation and exploratory factor analysis of the VTAS was conducted using data from two samples of spider-fearful patients treated with VRET and the help of an embodied, voice-based virtual therapist (n=70). Multiple regression models and bivariate correlations were used to assess the VTAS relationship with treatment outcome, according to self-reported fear and convergence with presence and user-friendliness process measures. RESULTS: The VTAS showed a sound two-factor solution composed of a primary factor covering task, goal, and copresence; adequate internal consistency; and good convergent validity, including moderate correlation (r=.310, P=.01) with outcomes over follow-up. CONCLUSIONS: These preliminary results suggest that alliance toward a virtual therapist is a significant predictor of treatment outcome, favors the importance of a task-goal over bond-factor, and should be explored in studies with larger sample sizes and in additional forms of embodiment.


Subject(s)
Psychometrics/methods , Telemedicine/methods , Virtual Reality Exposure Therapy/methods , Factor Analysis, Statistical , Female , Humans , Male , Surveys and Questionnaires , Treatment Outcome
7.
Front Psychiatry ; 11: 116, 2020.
Article in English | MEDLINE | ID: mdl-32210850

ABSTRACT

BACKGROUND: Virtual Reality exposure therapy (VRET) is an evidence-based treatment of phobias and recent research suggests that this applies also to self-contained, automated interventions requiring no therapist guidance. With the advent and growing adoption of consumer VR technology, automated VR intervention have the potential to close the considerable treatment gap for specific phobias through dissemination as consumer applications, self-help at clinics, or as blended treatment. There is however a lack of translational effectiveness studies on VRET treatment effects under real-world conditions. METHODS: We conducted a single-arm (n = 25), single-subject study of automated, gamified VRET for fear of spiders, under simulated real-world conditions. After setup and reading instructions, participants completed the automated, single-session treatment by themselves. Self-rated fear of spiders and quality of life served as outcome measures, measured twice before, and one and two weeks after treatment, and at a six-month follow-up. Session characteristics and user experience measures were collected at the end of the session. RESULTS: Mixed-effects modeling revealed a significant and large (d = 1.26) effect of treatment-onset on phobia symptoms (p < .001), and a small (d = 0.49) effect on quality of life (p = .025). Results were maintained at a six-month follow-up (p > .053). The intervention was tolerable and practical. There were no significant correlations between any user experience measure and decrease in phobia symptoms (p > .209). CONCLUSIONS: An automated VRET intervention for fear of spiders showed equivalent effects on phobia symptoms under effectiveness conditions as previously reported under efficacy conditions. These results suggest that automated VRET applications are promising self-help treatments also when provided under real-world conditions. PRE-REGISTRATION: Open Science Foundation, https://doi.org/10.17605/OSF.IO/78GUB.

9.
Front Psychiatry ; 10: 792, 2019.
Article in English | MEDLINE | ID: mdl-31736809

ABSTRACT

Depression is a common mental disorder with a large treatment gap. Low-intensity, automated virtual reality (VR) interventions (not requiring a therapist) is a scalable and promising solution now that VR is an accessible and mature, consumer technology. Yet unlike with phobias, there have been few attempts at translating evidence-based cognitive behavioral therapeutic (CBT) techniques for depression into the VR modality. In this paper, we discuss how specific CBT techniques can be made into VR experiences, including psychoeducation, behavioral activation, cognitive restructuring, and social skills training. We also discuss how VR-unique experiences, such as alternative embodiment and virtual pet interactions, can be made therapeutic. Creating a pre-clinical and clinical evidence base for these types of novel interventions should be considered a research priority, and high-quality development on par with other consumer VR applications will be essential to the success of any consumer-targeted intervention. If this is achieved, low-intensity VR interventions for depression have great potential to make an impact on public mental health.

10.
Behav Res Ther ; 118: 130-140, 2019 07.
Article in English | MEDLINE | ID: mdl-31075675

ABSTRACT

OBJECTIVE: This study compared the efficacy of a technician-assisted single-session virtual reality exposure therapy (VRET) for the treatment of spider phobia featuring low-cost consumer-available hardware and novel automated software to gold-standard in-vivo one-session treatment (OST), using a parallel group randomized non-inferiority design. Method Participants (N = 100) were randomized to VRET and OST arms. Assessors blinded to treatment allocation evaluated participants at pre- and post-treatment as well follow-up (3 and 12 months) using a behavioral approach test (BAT) and self-rated fear of spider, anxiety, depression and quality-of-life scales. A maximum post-treatment difference of 2-points on the BAT qualified as non-inferiority margin. Results Linear mixed models noted large, significant reductions in behavioral avoidance and self-reported fear in both groups at post-treatment, with VRET approaching the strong treatment benefits of OST over time. Non-inferiority was identified at 3- and 12- months follow-up but was significantly worse until 12-months. There was no significant difference on a questionnaire measuring negative effects. Conclusions Automated VRET efficaciously reduced spider phobia symptoms in the short-term and was non-inferior to in-vivo exposure therapy in the long-term. VRET effectiveness trials are warranted to evaluate real-world benefits and non-specific therapeutic factors accruing from the presence of a technician during treatment. ClinicalTrials.gov (NCT02533310).


Subject(s)
Phobic Disorders/therapy , Virtual Reality Exposure Therapy/methods , Adult , Animals , Female , Humans , Male , Middle Aged , Phobic Disorders/psychology , Spiders , Treatment Outcome , Young Adult
12.
Front Psychol ; 10: 176, 2019.
Article in English | MEDLINE | ID: mdl-30800086

ABSTRACT

Virtual reality exposure therapy (VRET) is an efficacious treatment for fear and anxiety and has the potential to solve both logistic issues for therapists and be used for scalable self-help interventions. However, VRET has yet to see large-scale implementation in clinical settings or as a consumer product, and past research suggests that while therapists may acknowledge the many advantages of VRET, they view the technology as technically inaccessible and expensive. We reasoned that after the 2016 release of several consumer virtual reality (VR) platforms and associated public acquaintance with VR, therapists' concerns about VRET may have evolved. The present study surveyed attitudes toward and familiarity with VR and VRET among practicing cognitive behavior therapists (n = 185) attending a conference. Results showed that therapists had an overall positive attitude toward VRET (pros rated higher than cons) and viewed VR as applicable to conditions other than anxiety. Unlike in earlier research, high financial costs and technical difficulties were no longer top-rated negative aspects. Average negative attitude was a larger negative predictor of self-rated likelihood of future use than positive attitude was a positive predictor and partially mediated the positive association between VRET knowledge and likelihood of future use, suggesting that promotional efforts should focus on addressing concerns. We conclude that therapist's attitudes toward VRET appear to have evolved in recent years, and no longer appear to constitute a major barrier to implementing the next generation of VR technology in regular clinical practice.

13.
Front Psychol ; 10: 132, 2019.
Article in English | MEDLINE | ID: mdl-30778311

ABSTRACT

Virtual Reality (VR) technology can be used to create immersive environments that promote relaxation and distraction, yet it is only with the recent advent of consumer VR platforms that such applications have the potential for widespread dissemination, particularly in the form of consumer-targeted self-help applications available at regular digital marketplaces. If widely distributed and used as intended, such applications have the potential to make a much-needed impact on public mental health. In this study, we report real-world aggregated uptake, usage and application performance statistics from a first-generation consumer-targeted VR relaxation application which has been publicly available for almost 2 years. While a total of 40,000 unique users signals an impressive dissemination potential, average session duration was lower than expected, and the data suggests a low number of recurrent users. Usage of headphones and auxiliary input devices was relatively low, and some application performance issues were evident (e.g., lower than intended framerate and occurrence of overheating). These findings have important implications for the design of the future VR relaxation applications, revealing primarily that user engagement needs to be addressed in the early stage of development by including features that promote prolonged and recurrent use (e.g., gamification elements).

14.
J Anxiety Disord ; 61: 45-54, 2019 01.
Article in English | MEDLINE | ID: mdl-30054173

ABSTRACT

Public speaking anxiety (PSA) is a common condition which can be treated effectively with exposure therapy. However, inherent difficulties in stimuli presentation and control limits dissemination and the therapeutic potential. Virtual Reality (VR) technology has the potential to resolve these issues and provide a scalable platform for self-help interventions. No previous study has examined whether this can be achieved using the first generation of consumer VR hardware and software. In the current trial, n = 25 + 25 participants were randomized to either one-session therapist-led VR exposure therapy for PSA followed by a four-week internet-administered VR to in-vivo transition program, or a waiting-list. Linear mixed effects modeling revealed significant, large (within Cohen's d = 1.67) decreases in self-reported PSA. The waiting-list was then given access to an internet-administered, self-led version of the same VR exposure therapy to be conducted at home, followed by the same transition program. Dual-slope mixed effects modeling revealed significant, large (d = 1.35) decreases in self-reported PSA. Results were maintained or improved at six- and twelve-month follow-ups. We show for the first time that low-cost, off-the-shelf consumer VR hardware and software can be used to conduct exposure therapy for PSA, both in the traditional, previously impractical one-session format, and in a novel self-led, at-home format.


Subject(s)
Anxiety Disorders/therapy , Anxiety/therapy , Self Care , Software , Speech , Virtual Reality Exposure Therapy/methods , Adult , Female , Humans , Implosive Therapy/methods , Male
15.
Scand J Psychol ; 60(1): 1-6, 2019 Feb.
Article in English | MEDLINE | ID: mdl-30556593

ABSTRACT

Spider phobia is a common and impairing mental disorder, yet little is known about what characteristics of spiders that spider phobic individuals find frightening. Using screening data from a clinical trial, we explored which characteristics that spider-fearful individuals (n = 194) rated as having the greatest impact on fear, used factor analysis to group specific characteristics, and explored linear associations with self-reported phobia symptoms. Second, a guided text-mining approach was used to extract the most common words in free-text responses to the question: "What is it about spiders that you find frightening?" Both analysis types suggested that movement-related characteristics of spiders were the most important, followed by appearance characteristics. There were, however, no linear associations with degree of phobia symptoms. Our findings reveal the importance of targeting movement-related fears in in-vivo exposure therapy for spider phobia and using realistically animated spider stimuli in computer-based experimental paradigms and clinical interventions such as Virtual Reality exposure therapy.


Subject(s)
Phobic Disorders/physiopathology , Spiders , Adult , Animals , Data Mining , Humans , Phobic Disorders/rehabilitation , Self Report , Virtual Reality Exposure Therapy
16.
Cogn Behav Ther ; 46(5): 404-420, 2017 09.
Article in English | MEDLINE | ID: mdl-28270059

ABSTRACT

Decades of research and more than 20 randomized controlled trials show that Virtual Reality exposure therapy (VRET) is effective in reducing fear and anxiety. Unfortunately, few providers or patients have had access to the costly and technical equipment previously required. Recent technological advances in the form of consumer Virtual Reality (VR) systems (e.g. Oculus Rift and Samsung Gear), however, now make widespread use of VRET in clinical settings and as self-help applications possible. In this literature review, we detail the current state of VR technology and discuss important therapeutic considerations in designing self-help and clinician-led VRETs, such as platform choice, exposure progression design, inhibitory learning strategies, stimuli tailoring, gamification, virtual social learning and more. We illustrate how these therapeutic components can be incorporated and utilized in VRET applications, taking full advantage of the unique capabilities of virtual environments, and showcase some of these features by describing the development of a consumer-ready, gamified self-help VRET application for low-cost commercially available VR hardware. We also raise and discuss challenges in the planning, development, evaluation, and dissemination of VRET applications, including the need for more high-quality research. We conclude by discussing how new technology (e.g. eye-tracking) can be incorporated into future VRETs and how widespread use of VRET self-help applications will enable collection of naturalistic "Big Data" that promises to inform learning theory and behavioral therapy in general.


Subject(s)
Anxiety Disorders/therapy , Software Design , Virtual Reality Exposure Therapy , Humans , Self Care/trends , Therapy, Computer-Assisted/trends
17.
Trials ; 17: 60, 2016 Feb 02.
Article in English | MEDLINE | ID: mdl-26833396

ABSTRACT

BACKGROUND: Traditional one-session exposure therapy (OST) in which a patient is gradually exposed to feared stimuli for up to 3 h in a one-session format has been found effective for the treatment of specific phobias. However, many individuals with specific phobia are reluctant to seek help, and access to care is lacking due to logistic challenges of accessing, collecting, storing, and/or maintaining stimuli. Virtual reality (VR) exposure therapy may improve upon existing techniques by facilitating access, decreasing cost, and increasing acceptability and effectiveness. The aim of this study is to compare traditional OST with in vivo spiders and a human therapist with a newly developed single-session gamified VR exposure therapy application with modern VR hardware, virtual spiders, and a virtual therapist. METHODS/DESIGN: Participants with specific phobia to spiders (N = 100) will be recruited from the general public, screened, and randomized to either VR exposure therapy (n = 50) or traditional OST (n = 50). A behavioral approach test using in vivo spiders will serve as the primary outcome measure. Secondary outcome measures will include spider phobia questionnaires and self-reported anxiety, depression, and quality of life. Outcomes will be assessed using a non-inferiority design at baseline and at 1, 12, and 52 weeks after treatment. DISCUSSION: VR exposure therapy has previously been evaluated as a treatment for specific phobias, but there has been a lack of high-quality randomized controlled trials. A new generation of modern, consumer-ready VR devices is being released that are advancing existing technology and have the potential to improve clinical availability and treatment effectiveness. The VR medium is also particularly suitable for taking advantage of recent phobia treatment research emphasizing engagement and new learning, as opposed to physiological habituation. This study compares a market-ready, gamified VR spider phobia exposure application, delivered using consumer VR hardware, with the current gold standard treatment. Implications are discussed. TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT02533310. Registered on 25 August 2015.


Subject(s)
Clinical Protocols , Phobic Disorders/therapy , Spiders , Virtual Reality Exposure Therapy/methods , Adult , Animals , Humans , Outcome Assessment, Health Care
18.
Internet Interv ; 6: 107-114, 2016 Nov.
Article in English | MEDLINE | ID: mdl-30135819

ABSTRACT

The purpose of this article is to describe an internet-based platform for improving symptoms and quality of life for people with psychological and behavioural health problems such as depression, anxiety, phobia, psychological trauma, hearing loss and tinnitus. The online platform, called Iterapi, was developed at the Department of Behavioural Sciences and Learning at Linköping University, Sweden and has been running for nearly two decades and used in many randomized controlled trials and outpatient treatments. The intention of this article is to share our experience with developing such a treatment solution and the process flow and elements of running internet-based psychological interventions. This will likely be of use to developers building similar services, therapists considering integrating such approaches in their practices and institutions, as well as researchers curious about the functions included on the platform and methodology used for running studies. We describe the security aspects of the platform, central concepts underlying its development, how the platform can be used in a study or treatment and the main features and functions the platform offers. We comment on practical considerations regarding blending of methods within the platform, such as self-help treatments with asynchronous communication and real-time text chat and video conversations. We also point out the advantages of using Internet-assisted treatments, the challenges that we have faced and future planned upgrades. Due to continuous development of the platform, its user-friendliness, accessibility across devices and numerous features, many research colleagues from Sweden as well as other countries such as Germany, United Kingdom, Romania and Israel have chosen to implement their own studies on the platform.

19.
Crit Rev Food Sci Nutr ; 55(9): 1246-69, 2015.
Article in English | MEDLINE | ID: mdl-24915386

ABSTRACT

HarvestPlus, part of the Consultative Group on Internation Agriculture research (CGIAR) Program on Agriculture for Nutrition and Health (A4NH) uses conventional plant breeding techniques to develop staple food crops that are rich in micronutrients, a food-based approach to reduce micronutrient malnutrition known as biofortification. The nutritional breeding targets are established based on the food intake of target populations, nutrient losses during storage and processing and bioavailability. This review collates the evidence on the retention of provitamin A carotenoid (pVAC) after processing, cooking, and storing of the staple crops targeted for pVAC biofortification: cassava, maize, and sweet potato. Sun drying was more detrimental to the pVAC levels (27-56% retention) in cassava than shade (59%) or oven (55-91%) drying, while the pVAC retention levels (66-96%) in sweet potato were not significantly different among the various drying methods. Overall, boiling and steaming had higher pVAC retention (80-98%) compared to baking (30-70%) and frying (18-54%). Gari, the most frequently consumed form of cassava in West Africa had the lowest pVAC retention (10-30%). The pVAC retention of maize grain and cassava and sweet potato flour reached levels as low as 20% after 1-4 months of storage and was highly dependent on genotype. Therefore, we recommend that an evaluation of the pVAC degradation rate among different genotypes be performed before a high pVAC crop is promoted.


Subject(s)
Carotenoids/analysis , Food Handling/methods , Food, Fortified , Ipomoea batatas/chemistry , Manihot/chemistry , Zea mays/chemistry , Africa , Biological Availability , Breeding , Carotenoids/pharmacokinetics , Crops, Agricultural/chemistry , Food Storage/methods , Humans , Micronutrients/analysis , Vitamin A/analysis
20.
Food Nutr Bull ; 31(2): 214-20, 2010 Jun.
Article in English | MEDLINE | ID: mdl-20707227

ABSTRACT

BACKGROUND: Iodine deficiency has serious consequences, and the Universal Salt iodization initiative has attempted to reduce the extent of deficiency. OBJECTIVE: We aim to see how far across-country variations in urinary iodine in school-age children can be explained by environmental factors, particularly soil iodine and the availability of iodized salt. METHODS: We use simple multivariate regression for two separate datasets, one for 30 developing countries, and one for 13 developed countries, using data on availability of iodized salt and soil iodine levels. RESULTS: Median urinary iodine excretion is significantly and positively related to household availability of iodized salt (elasticity, 0.73) for developing countries, but the soil coefficient is not significant, probably because the dummy variable is not well measured. For the developed countries, there is a positive and significant effect of salt penetration rates (elasticity, 0.83) and a positive and significant effect of soil iodine (elasticity, 0.77). There is also a suggestion that countries with more serious soil deficits are more likely to iodize salt, so that univariate regressions of urinary iodine excretion on salt availability or penetration rates underestimate the beneficial effects of iodized salt availability on iodine nutrition. CONCLUSIONS: There are limitations to cross-sectional (ecologic) studies such as this, and the data are not perfect. Nevertheless, the results provide support for policies to iodize salt, given the widespread deficiency of iodine in diets worldwide.


Subject(s)
Global Health , Iodine/administration & dosage , Nutritional Status , Sodium Chloride, Dietary/supply & distribution , Child , Cross-Sectional Studies , Databases, Factual , Developed Countries/statistics & numerical data , Developing Countries/statistics & numerical data , Family Characteristics , Humans , Iodine/analysis , Iodine/deficiency , Iodine/supply & distribution , Iodine/urine , Models, Statistical , Nutrition Policy , Soil/analysis
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