Publications

The mouse is increasingly important as a subject of vestibular research. Although many studies have focused on the vestibular responses of mice to angular rotation, the geometry of their semicircular canals has not been described. High-voltage X-ray computed tomography was used to measure the anatomy of the semicircular canals of two strains of mice, C57Bl/6J and CBA/CaJ. The horizontal plane of a stereotaxic coordinate system was defined by the midpoints of the external auditory meati and the point where the incisors emerge from the maxilla. The centroids of the lumens of the bony canals were calculated, and planes that describe the canals were fit using a least-squares regression analysis to the resulting points. Vectors normal to each regressed plane were used to represent the corresponding canal's axis of rotation, and angles of these vectors relative to skull landmarks as well as to each other were calculated. The horizontal canal of the mouse was found to be angled anteriorly upward 17.8 degrees for CBA/CaJ and 32.6 degrees for C57Bl/6J from the reference horizontal plane. Angles between ipsilateral canals deviated up to 12.3 degrees from orthogonal, and angles between contralateral synergistic canals (left anterior-right posterior, right anterior-left posterior, and horizontal-horizontal) deviated from parallel by up to 14.8 degrees. The orientations of the canals within the head as well as the orientations of the canals relative to each other were significantly different between the two strains, suggesting that care must be taken in the design and interpretation of developmental and physiologic studies involving different mouse strains.

OBJECTIVE

To estimate costs of routine care for female urinary incontinence, health-related quality of life, and willingness to pay for incontinence improvement.

METHODS

In a cross-sectional study at 5 U.S. sites, 293 incontinent women quantified supplies, laundry, and dry cleaning specifically for incontinence. Costs were calculated by multiplying resources used by national resource costs and presented in 2005 United States dollars (2005). Health-related quality of life was estimated with the Health Utilities Index. Participants estimated willingness to pay for 25-100% improvement in incontinence. Potential predictors of these outcomes were examined using multivariable linear regression.

RESULTS

Mean age was 56 +/- 11 years; participants were racially diverse and had a broad range of incontinence severity. Nearly 90% reported incontinence-related costs. Median weekly cost (25%, 75% interquartile range) increased from 0.37 dollars (0, 4 dollars) for slight to 10.98 dollars (4, 21 dollars) for very severe incontinence. Costs increased with incontinence severity (P < .001). Costs were 2.4-fold higher for African American compared with white women (P < .001) and 65% higher for women with urge compared with those having stress incontinence (P < .001). More frequent incontinence was associated with lower Health Utilities Index score (mean 0.90 +/- 0.11 for weekly and 0.81 +/- 0.21 for daily incontinence; P = .02). Women were willing to pay a mean of 70 dollars +/- 64 dollars per month for complete resolution of incontinence, and willingness to pay increased with income and greater expected benefit.

CONCLUSION

Women with severe urinary incontinence pay 900 dollars annually for incontinence routine care, and incontinence is associated with a significant decrement in health-related quality of life. Effective incontinence treatment may decrease costs and improve quality of life.

LEVEL OF EVIDENCE

III.