Improved accuracy of co-morbidity coding over time after the introduction of ICD-10 administrative data.

BACKGROUND: Co-morbidity information derived from administrative data needs to be validated to allow its regular use. We assessed evolution in the accuracy of coding for Charlson and Elixhauser co-morbidities at three time points over a 5-year period, following the introduction of the International Classification of Diseases, 10th Revision (ICD-10), coding of hospital discharges.METHODS: Cross-sectional time trend evaluation study of coding accuracy using hospital chart data of 3'499 randomly selected patients who were discharged in 1999, 2001 and 2003, from two teaching and one non-teaching hospital in Switzerland. We measured sensitivity, positive predictive and Kappa values for agreement between administrative data coded with ICD-10 and chart data as the 'reference standard' for recording 36 co-morbidities.RESULTS: For the 17 the Charlson co-morbidities, the sensitivity - median (min-max) - was 36.5% (17.4-64.1) in 1999, 42.5% (22.2-64.6) in 2001 and 42.8% (8.4-75.6) in 2003. For the 29 Elixhauser co-morbidities, the sensitivity was 34.2% (1.9-64.1) in 1999, 38.6% (10.5-66.5) in 2001 and 41.6% (5.1-76.5) in 2003. Between 1999 and 2003, sensitivity estimates increased for 30 co-morbidities and decreased for 6 co-morbidities. The increase in sensitivities was statistically significant for six conditions and the decrease significant for one. Kappa values were increased for 29 co-morbidities and decreased for seven.CONCLUSIONS: Accuracy of administrative data in recording clinical conditions improved slightly between 1999 and 2003. These findings are of relevance to all jurisdictions introducing new coding systems, because they demonstrate a phenomenon of improved administrative data accuracy that may relate to a coding 'learning curve' with the new coding system.

Anxiety and Psychological Stress Before Prenatal Screening in First-Time Mothers Who Conceived Through IVF/ICSI or Spontaneously.

Mothers' general anxiety, anxiety about the well-being of the child and psychological stress before prenatal testing was studied by comparing women who conceived through in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) with women who conceived naturally. Before the first trimester screening test for Down's syndrome, a group of 51 women who conceived through IVF/ICSI and a group of 54 women who conceived spontaneously completed the State Scale of the State-Trait Anxiety Inventory (S-Anxiety; Spielberger, 1983), the Fear of Bearing a Physically or Mentally Handicapped Child Subscale of the Pregnancy-related Anxiety Questionnaire (PRAQ-R; Huizink et al., 2004), the Psychological Stress Measure (PSM; Lemyre & Tessier, 1988), and the Prenatal Psychosocial Profile (PPP; Curry, Campbell, & Christian, 1994). Women who conceived through IVF/ICSI had more elevated levels of general anxiety and psychological stress than the women who conceived naturally; however, no difference was observed between the two groups for anxiety specifically related to the health of the child. These results underline the need to monitor women's emotional state after conception via IVF/ICSI-when counseling usually ends-and around the time of the first trimester screening. Counseling might thus be extended.

Continuous-time formulation of reaction-diffusion processes on heterogeneous metapopulations

We present the derivation of the continuous-time equations governing the limit dynamics of discrete-time reaction-diffusion processes defined on heterogeneous metapopulations. We show that, when a rigorous time limit is performed, the lack of an epidemic threshold in the spread of infections is not limited to metapopulations with a scale-free architecture, as it has been predicted from dynamical equations in which reaction and diffusion occur sequentially in time