Transcript Ingelmo Trindade

Journal Club:
“Role of Gastroesophageal
Reflux Symptoms in
Exacerbations of COPD”
October 19, 2006
Christopher Ingelmo
Anil J. Trindade
J. Hunter Young
Results:
GERD (+) = “Weekly symptomatic GERD over the past year” based on
the Mayo Survey.
Comparison of Exacerbation Type
1) GERD (+) patients had significantly increased rates of COPD exacerbations (p=0.02),
hospitalizations (p=0.007), ER visits (p=0.005), unscheduled clinic appointments (p=0.01)
and antibiotic use (p=0.01) compared to GERD (-) patients.
2) There was no significant difference in corticosteroid use between GER+ and GERpatients.
Patient Demographics:
There are no statistically significant differences between the
GER+ and GER- groups in terms of age, gender, smoking
status, severity of airway obstruction, BMI or coffee and/or
EtOH use.
Use of GERD-related Pharmacotherapy:
1) The majority of patients (61/86) were taking an anti-reflux
medicine.
2) A third of the patients were on combination therapy.
3) A significantly greater amount of patients taking antacids had
GER symptoms weekly.
Break it down.
1) Trend toward increased
number of COPD
exacerbations in GER+
patients regardless of reflux
pharmacotherapy.
1) Non-significant trend toward
increased COPD
exacerbations in GER+
patients, irrespective of
severity of airway obstruction.
2) Trend toward increased
COPD exacerbations in those
with GER+ weekly symptoms,
irrespective of smoking status.
Discussion:
Were the Aims of the study Met?:
a) Demonstrate prevalence of symptomatic GERD in the sampled
population (those with COPD)
i) 36% of COPD patients had GER Sx compared to general US
population of 14-19%
b) Determine if an epidemiologic association between GER symptoms and
exacerbations of COPD existed
i) Overall there was a significantly increased rate of COPD
exacerbations in those with GER+ symptoms compared to those
without (p=0.02)
ii) When controlled for severity of airway disease, non-signif trend
toward increased exacerbations in those with GER+ symptoms
Does GERD cause increased COPD Exacerbations?
Association vs. Causality








Temporality  cause precedes effect
Dose Response
Reversibility  Lower disease rates with reduced exposure.
Consistency  repeatedly observed in different people, places,
circumstances and time.
Biologic plausibility
Specificity  one cause leads to one effect
Analogy  Cause-effect relationship established for similar exposure
or disease.
Strength of the Association large relative risk
…Limitations of a Cross-sectional / Prevalence Study…
Precautions:

Recall Bias

Confounding Bias
a) Risk factors for GERD  age, BMI, caffeine/EtOH
b) Can GERD-therapies cause exacerbations?
c) Can COPD-therapies cause GERD?
“Oral Corticosteroids Increase Esophageal Acid Contact Times in
Patients with Stable Asthma.” Chest. 2002;121:625-634.)
Conclusion


“Findings suggest a possible modifiable risk factor in
exacerbations of COPD.”
Cross sectional study is an easy way to show an
association between a risk factor and a disease.
What’s Next?

Longitudinal study to help show causality
References:

Rascon-Aguilar, et al. “ Role of Gastroesophageal Reflux
Symptoms in Exacerbations of COPD.” Chest 2006; 130:
1096-1101.

Lazenby, etal. “Oral Corticosteroids Increase Esophageal Acid
Contact Times in Patients with Stable Asthma.” Chest 2002;
121: 625-634.

Fletcher RW, Fletcher SW. “Clinical Epidemiology: The
Essentials. 4th Edition” Lippincott Williams & Wilkins. 2005