Readmissions to Hospital Among Patients With COPD After Telemedicine Video Consultation - a Pilot Project

The study is conducted as a retrospective uni-center observation study of a population of COPD patients who after discharge from hospital for acute COPD exacerbation, or during outpatient treatment for acute COPD exacerbation, was monitored for 2 weeks by TVC during a pilot project period from 16 April 2010 to 31 December 2011. To study a possible change in amount of hospital admissions we have compared the frequencies and durations of such events before and after TVC in comparable time periods.

A detailed patient history comprising demographic data, social status, smoking habits, body mass index (BMI), use of medication, co-morbidity and the habitual lung function were registered. Dates of admittance and discharge were noted. Retrospectively, medical records were scrutinized for re-admissions due to COPD exacerbations at 12 months follow-up. Frequency of and date of re-admissions, length of hospital stay, and clinical data were recorded. Also frequency of admission due to COPD exacerbation and length of hospital stay(s) during the last 12 months prior to the TVC were recorded, and date of last discharge was noted. Finally, all patients were encouraged to complete a questionnaire concerning patient satisfaction and impact on patient's quality of life. All answers were registered anonymously.

Data were entered to a database by one trained nurse and monitored by another person, who compared data entered into the registry against predefined rules for range or consistency with other data fields in the registry. All patients who had been monitored by TVC during the pilot project period, gave informed consent to participate in the observational study, and no patient was lost to follow-up.

Continuously distributed variables of baseline characteristics were given as mean + SEM, while variables with more skewed distributions were given as median and upper and lower quartiles.

The Shapiro-Wilk test for normality was performed to study the distribution of parameters. A chi-square test was applied to compare the frequency of re-admissions during 12 months following TVC to the frequency of hospital admissions during the last 12 months prior to TVC. The total number of days in hospital during the last 12 months prior to TVC was compared to number of days in hospital during 12 months following TVC by a paired t-test. Differences in baseline characteristics between patients who were re-admitted and those who were not, were analyzed by a Two-sample Student's T-test, or in case of non-normality, by the Mann-Whitney Rank Sum test.

The number of days to re-admission following TVC as compared to number of days from last discharge to date of index admittance was displayed in a Kaplan Meier plot, with a hazard ratio (HR) calculation by a by a Cox regression analysis.

A statistically significant level of p < 0.05 was applied for all tests. All statistical analyses were performed using the statistical package of SigmaPlot Version 12.

Power calculations have not been performed for the purpose of this pilot study, because of too many unknown factors. The results of this study will form the basis of power calculations for a future prospective randomized study.