chronic obstructive pulmonary disease (copd) is a major cause of chronic morbidity and mortality...
TRANSCRIPT
Chronic Obstructive Pulmonary Disease (COPD) is a major cause of chronic morbidity and mortality worldwide and in Singapore. In Singapore, there are about 60,000 cases of COPD. They constitute about 1/5 of all deaths and 7th principal cause of death and 7th most common condition for hospitalization in Singapore (2010). The Airway Programme (TAP) was started in 2008 in three hospitals – Tan Tock Seng Hospital, National University Hospital and Alexandra Hospital. The programme aimed to optimise resources to enable better management of patients afflicted with COPD and Community Acquired Pneumonia (CAP). The objectives of TAP were •To reduce hospitalisations for acute exacerbations of COPD and prevent premature hospitalisations for CAP •To reduce the average length of stay (ALOS) for patients with COPD; and improve quality of life of patients with COPD and/or afflicted with CAP and•Improve quality of life of patients with COPD and/or afflicted with CAP
BACKGROUND
RESEARCH OBJECTIVE
CONCLUSIONSParticipation in “TAP” was associated with lower all-cause mortality when compared to the controls. The survival gain in the TAP patients was associated with an increase in total hospital days. Risk of readmission was higher for TAP patients after adjusting for mortality (competing risk). Evaluation of such program by means of administrative databases may yield meaningful results. Further studies are required to ensure corrections for in case mix and time bias.
LimitationsThe evaluation focuses only on patients with hospitalization and hence not representative of all COPD patients. The analysis has not been adjusted for disease severity, but only adjusted for demographics and comorbidities. Readmission that were analyzed were only from AH, NUH and TTSH, admissions/ readmissions that happened outside of these are not captured. Lastly, the evaluation assessed only association, not causality.
To assess the impact of “The air way program” (COPD) on patients length of stay, readmission and mortality.
1Health Services & Outcomes Research (HSOR), National Healthcare Group, Singapore, 2Disease management, National Healthcare Group, 3National Healthcare Group Polyclinics, Singapore, Singapore, 4National University Hospital, Singapore, Singapore
Pradeep Paul George1*, Bee Hoon Heng1, Mavis Yeow Bee Ling2, Loo See Yeow2,3, Fong Seng Lim2,3, Lim Tow Keang4
Participation in “The Airways Program” (TAP) and associated mortality reduction
METHODSTAP patients were compared with controls, who were COPD patients (DRG 177) and fulfilled the programme’s inclusion criteria but were not enrolled in the programme. Control patients were identified from Operations Data Store and Central Clinical Research Database. Patients who had hospitalisations after enrolment or refusal till December 2009 were analysed. Outcomes of interest were hospital length of stay, re-admission and mortality. T-test and chi-square test were used to compare continuous and categorical variables respectively.
Risk of death and risk of readmission was estimated using cox and competing risk regression respectively. Propensity score was estimated to identify the predictors of program enrolment. Variables used for propensity score computation were age, gender, race, hospital, ward class, comorbidities: asthma, diabetes, hypertension, stroke, congestive heart failure, dyslipidemia and obesity. TAP patients and controls were matched on their propensity score using nearest neighbor without replacement methodology.
RESULTSThere were 170 matched TAP patients and controls patients, they had 287 and 207 hospitalizations respectively. TAP patients and controls were similar with regards to age and gender and average hospital length of stay (P<0.05). No of days admitted to hospital per 100 person days were higher for TAP patients (Table 1).
Table 1 Comparison of characteristics, TAP patients vs. controls
¶ Person time (days) – Program: 55527 and Controls: 47295
Table:3 Risk of death, hazard ratio and 95% CI
Table : 2 Readmission rate among TAP patients and controls
Table:4 Risk of readmission, sub hazard ratio and 95% CI
VariablesTAP
patients(n = 170)
Controls(n = 170)
P value
Episodes 287 207
ALOS ± SD (days) 4.2 ± 4.7 4.3 ± 4.9 0.822
Total hospital days 1207 891
Avg. hospital days / patient 7.1 5.2
Total person-years of follow up 152.02 129.49
Total hospital days per 100 person-days¶ 2.2 1.9
0.0012
Total no of deaths, n (%) 18 (11) 35 (21) 0.0105
Deaths due to respiratory system diseases
15 (9) 26 (15)0.0664
All cause mortality rate per person-year.
0.12 0.270.0036
Mortality due to respiratory system diseases per person-year
0.09 0.20 0.0282
Status nPerson-
time (years)
Patient with readmission
s(n)
Readmission rate
95% CI
TAP patients 170 140.99 51 0.36 0.270.48
Control patients
170 126.12 22 0.17 0.110.26
Variables SHR*95% Confidence Interval
(CI) P valueLower Upper
Age 1.01 0.97 1.04 0.65Females 1.19 0.57 2.51 0.65Malay 0.57 0.17 1.84 0.35Indian 1.49 0.60 3.73 0.39NUH 0.51 0.17 1.58 0.25TTSH 1.16 0.51 2.63 0.73Ward class B 0.86 0.28 2.68 0.80Ward class C 1.12 0.38 3.30 0.84Asthma 1.55 0.81 2.96 0.19Diabetes Mellitus 0.44 0.19 1.02 0.05Hypertension 0.98 0.53 1.79 0.94Stroke 0.91 0.30 2.73 0.87Coronary Heart Disease 0.83 0.36 1.92 0.67Heart Failure 0.87 0.32 2.37 0.79Dyslipidemia 1.09 0.51 2.31 0.83Obesity 1.37 0.69 2.72 0.36TAP patients 3.40 1.81 6.39 0.00
VariablesHazard Ratio
95% Confidence Interval (CI)
P valueLower Upper
Age 1.04 1.00 1.08 0.05Females 0.50 0.17 1.46 0.21NUH 0.83 0.31 2.22 0.71TTSH 0.83 0.35 1.99 0.68Ward class B 0.62 0.13 2.89 0.54Ward class C 1.15 0.26 5.05 0.86Readmission 1.99 1.09 3.61 0.03Asthma 0.37 0.18 0.78 0.01Diabetes Mellitus 2.27 1.20 4.30 0.01Hypertension 1.00 0.50 2.01 1.00Stroke 0.98 0.38 2.49 0.96Coronary Heart Disease
1.06 0.49 2.29 0.88
Heart Failure 1.00 0.44 2.27 1.00Dyslipidemia 1.18 0.57 2.43 0.66Obesity 0.22 0.08 0.65 0.01TAP patients 0.38 0.21 0.69 0.00
Hospital
TAP patients Controls
P valuePerson-daysΦ
Total hospital daysΦ
Hospital days per
100 person- days┼
Person-daysΦ
Total hospital daysΦ
Hospital days per
100 person- days┼
AH 7167 282 3.93 6078 81 1.33 0.00NUH 15389 257 1.67 12881 209 1.62 0.76TTSH 32556 667 2.05 28336 601 2.12 0.54 Total 55112 1206 2.19 47295 891 1.88 0.0007
Table:5 No of days admitted to hospital per 100 person-days
Risk of death was lower for program patients (Table 3). After controlling for competing risk death, the risk of readmission was 3.4 times higher for TAP patients when compared to controls (Table 4). No of hospital days per 100 person- days was significantly higher for TAP patients when compared to controls (Table 5).
All cause mortality and mortality due to respiratory system diseases were lower (Table 1) and readmission was higher for program patients (Table 2). 30-day readmission was significantly higher for program patients (0.14/person-year, 95% CI:0.09 – 0.22) when compared to controls (0.03/person-year, 95% CI: 0.01 – 0.08).
* SHR: Sub Hazard ratio
┼ # of days admitted to hospital per100 person days, Φ One patient from Singhealth not included in the total, hence the total person time and total hospital days would not add up to 55527 person-days and 1207 (total hospital days)
* For further information please contact [email protected]