Assessing dehydration status in dengue patients using urine colourimetry and mobile phone technology.

BACKGROUND: Dengue is a systemic and dynamic disease with symptoms ranging from undifferentiated fever to dengue shock syndrome. Assessment of patients' severity of dehydration is integral to appropriate care and management. Urine colour has been shown to have a high correlation with overall assessment of hydration status. This study tests the feasibility of measuring dehydration severity in dengue fever patients by comparing urine colour captured by mobile phone cameras to established laboratory parameters. METHODOLOGY/PRINCIPAL FINDINGS: Photos of urine samples were taken in a customized photo booth, then processed using Adobe Photoshop to index urine colour into the red, green, and blue (RGB) colour space and assigned a unique RGB value. The RGB values were then correlated with patients' clinical and laboratory hydration indices using Pearson's correlation and multiple linear regression. There were strong correlations between urine osmolality and the RGB of urine colour, with r = -0.701 (red), r = -0.741 (green), and r = -0.761 (blue) (all p-value <0.05). There were strong correlations between urine specific gravity and the RGB of urine colour, with r = -0.759 (red), r = -0.785 (green), and r = -0.820 (blue) (all p-value <0.05). The blue component had the highest correlations with urine specific gravity and urine osmolality. There were moderate correlations between RGB components and serum urea, at r = -0.338 (red), -0.329 (green), -0.360 (blue). In terms of urine biochemical parameters linked to dehydration, multiple linear regression studies showed that the green colourimetry code was predictive of urine osmolality (ß coefficient -0.082, p-value <0.001) while the blue colourimetry code was predictive of urine specific gravity (ß coefficient -2,946.255, p-value 0.007). CONCLUSIONS/SIGNIFICANCE: Urine colourimetry using mobile phones was highly correlated with the hydration status of dengue patients, making it a potentially useful hydration status tool.

A cross-sectional study of the demographic, cultural, clinical and rehabilitation associated variables predicting return to employment after disability onset in an Asian society.

OBJECTIVES: This study examined the rate of return to work, and to find demographic, clinical and functional factors associated with successful re-employment after in-patient rehabilitation. METHODS: We performed a cross-sectional cohort study of Singaporeans aged 15 and above who underwent inpatient rehabilitation in a Singapore hospital between 2000 and 2007. Phone interviews were conducted in 2007 to 2008, via a structured questionnaire to evaluate factors of return to work. RESULTS: Four hundred and eight patients met with the inclusion criteria, and 123 participants completed the questionnaire. Forty-five (44.7%) participants successfully returned to work with a mean time of 7 months post-discharge. Statistical significant differences were found between the "return to work" group and "non-return to work" group based on age group (p=0.04), education level (p=0.001), pre-morbid job category (0.013) and functional status (p<0.0005) as determined by Functional Independence Measure scores. Cox regression analysis controlling the period between discharge and survey indicated that higher FIM scores and higher education level predicted successful re-employment. CONCLUSION: This result re-affirmed the importance of functional status to the success of return-to-work in Singapore. Further qualitative studies might be useful in exploring the social or environmental factors affecting return-to-work outcomes.