Volume-Outcome Relation for Pulmonary Embolism Treatment: Association between Physician and Hospital Volume and 30-day Mortality

Summary. Objective: This study sets out to examine the
association between physician and hospital pulmonary embolism
(PE) caseload volume and subsequent patient outcomes
using 3-year nationwide population-based data in Taiwan.
Method: This study used claims data from the 2002–2004
National Health Insurance Research Database. The sample of
2761 PE inpatients was divided into three physician caseload
volume groups, <3 cases (low volume), 3–6 cases (medium
volume) and ‡7 cases (high volume), while the three hospital
volume groups were <42 cases (low volume), 42–110 cases
(medium volume) and ‡111 cases (high volume). A conditional
logistic regression model was performed to evaluate the effects
of caseload volume on 30-day mortality for PE treatment.
Results: Patients treated by low case volume physicians had
significantly higher mortality rates than those treated by
medium case volume (19.0% vs. 13.3%, P < 0.001) or high
case volume physicians (19.0% vs. 8.4%, P < 0.001). However,
no significant relationship was observed between 30-day
morality and hospital caseload volume (P = 0.697). The
regression shows that the adjusted odds of 30-day mortality
among patients of low case volume physicians were over twice
the mortality odds among patients of high case volume
physicians (OR = 2.164, P < 0.001), and odds ratios were
1.401 relative to medium case volume physicians patients
(P < 0.05). Conclusion: We conclude that an inverse PE
volume-outcome relationship does exist for physicians, but not
for hospitals. The skill or experience of an individual physician
is a more critical factor than hospital equipment, infrastructure
or staffing team in determining PE patient outcomes.
Keywords: 30-day mortality, pulmonary embolism, volumeoutcome.