Acute exacerbation of chronic obstructive pulmonary disease: influence of social factors in determining length of hospital stay and readmission rates.

BACKGROUND: Acute exacerbation of chronic obstructive pulmonary disease (AECOPD) is the leading reason for hospitalization in Canada and a significant financial burden on hospital resources. Identifying factors that influence the time a patient spends in the hospital and readmission rates will allow for better use of scarce hospital resources. OBJECTIVES: To determine the factors that influence length of stay (LOS) in the hospital and readmission for patients with AECOPD in an inner-city hospital. METHODS: Using the Providence Health Records, a retrospective review of patients admitted to St Paul's Hospital (Vancouver, British Columbia) during the winter of 2006 to 2007 (six months) with a diagnosis of AECOPD, was conducted. Exacerbations were classified according to Anthonisen criteria to determine the severity of exacerbation on admission. Severity of COPD was scored using the Global Initiative for Chronic Obstructive Lung Disease (GOLD) criteria. For comparative analysis, severity of disease (GOLD criteria), age, sex and smoking history were matched. RESULTS: Of 109 admissions reviewed, 66 were single admissions (61%) and 43 were readmissions (39%). The number of readmissions ranged from two to nine (mean of 3.3 readmissions). More than 85% of admissions had the severity of COPD equal to or greater than GOLD stage 3. The significant indicators for readmission were GOLD status (P<0.001), number of related comorbidities (OR 1.47, 95% CI 1.10 to 1.97; P<0.009) and marital status (single) (OR 4.18, 95% CI 1.03 to 17.02; P<0.046). The requirement for social work involvement during hospital admission was associated with a prolonged LOS (P<0.05). CONCLUSIONS: The results of the present study show that disease severity (GOLD status) and number of comorbidities are associated with readmission rates of patients with AECOPD. Interestingly, social factors such as marital status and the need for social work intervention are also linked to readmission rates and LOS, respectively, in patients with AECOPD.

Deoxynucleotides can replace dideoxynucleotides in minisequencing by arrayed primer extension.

Scientific literature describing arrayed primer extension and other array-based minisequencing technologies consistently cite the requirement for four fluorescent dideoxynucleotides (with concomitant absence/inactivation of deoxynucleotides) to ensure single-base extension and thus sequence-specific intensity data that can be interpreted as a base call or genotype. We present compelling evidence that fluorescent deoxynucleotides can reliably be used in microarray minisequencing experiments, generating fluorescent sequence extension intensity profiles that are homologous to the single-base extensions obtained with terminator dideoxynucleotides. Due to the almost 10-fold higher costs (and limited fluorophore choice) of many commercially available fluorescent dideoxynucleotides, compared to fluorescent deoxynucleotides, as well as other potentially constraining intellectual property and licensing issues, this hitherto dismissed microarray chemistry represents an important reevaluation in the field of array-based genotyping and related enzymology.