ASPIRATION PNEUMONIA EPIDEMIC
IN ELDERLY AMERICANS?
pneumonia may have become a lethal and costly epidemic in elderly Americans, according
to William B. Baine, MD, who presented a poster at the 39th Interscience Conference
on Antimicrobial Agents and Chemotherapy.
"Pneumonitis due to inhalation
of food and vomitus, commonly known as aspiration pneumonia, has become the second
most frequent principal diagnosis, trailing only that broad catchall designation,
'pneumonia, organism unspecified,' among hospitalizations of Medicare patients
for any of 55 different diagnoses indicating infection or inflammation of the
lungs," stated Dr. Baine, who is Senior Medical Advisor at the Center for
Outcomes and Effectiveness Research at the Agency for Health Care Policy and Research
(AHCPR) in Rockville, Md.
"One possible explanation
for the apparent increase in aspiration pneumonia is that hospitals are increasingly
likely to specify aspiration pneumonia to obtain the maximum allowable reimbursement
from Medicare," Dr. Baine continued. "Of greater concern is the possibility
that [these diagnoses] might be revealing a smoldering epidemic of aspiration
pneumonia among elderly patients."
SEVERAL DISEASE PROCESSES
The diagnosis of aspiration
pneumonia included two different disease processes, Dr. Baine explained. In one
version of the disease, regurgitated stomach acid passes down the windpipe and
reaches the lung. The result can be an acid burn, which renders lung tissue susceptible
to complicating infection. The other version often reflects other illnesses that
compromise the patient's ability to cough or swallow. For example, patients whose
throat muscles have been affected by stroke can be at high risk for aspiration
pneumonia. Uncoordinated swallowing misdirects saliva, food, or drink to the airways.
If the patient's cough reflex is too feeble, some of these materials may pass
into the lung--along with mouth and throat bacteria.
AHCPR researchers reviewed
Health Care Financing Administration computer files of Medicare hospital claims
for patients discharged from 1991 through 1996 to identify inpatient stays by
patients age 65 years or older with a principal diagnosis of aspiration pneumonia.
"From 1991 through 1996, the number of hospital discharges of Medicare patients
whose reason for admission was reported to be aspiration pneumonia increased by
76%, exceeding 100,000 cases in 1996 alone," Dr. Baine pointed out. "Over
that same interval, the number of elderly persons who had Medicare coverage grew
by less than 7%."
Yearly increases in the number
of hospitalizations for aspiration pneumonia per 100,000 persons were most marked
in the very old. Mean costs and Medicare hospital reimbursements were lowest for
white women, who showed the lowest case-fatality rate in hospital (23%). This
subgroup of patients had the shortest average hospital stay (10.4 days) and stay
in intensive care (0.8 days) and accounted for a mean Medicare payment to the
hospital of only $8,246. In contrast, black men, at highest risk of fatal outcome
(26%), had the longest average stay in hospital (14.2 days) and in intensive care
(1.1 days) and were responsible for the highest Medicare hospital reimbursements.
An additional 22% of patients discharged alive to home or self-care were dead
within 90 days of hospital admission; case-fatality rates at 90 days were even
higher in patients sent to home health care, an intermediate care or a skilled
nursing facility, or to another facility.
Among Medicare patients with
a principal diagnosis of aspiration pneumonia, the three most common secondary
diagnoses were volume depletion, congestive heart failure, and urinary tract infections.
Common discharge diagnoses most strongly related to a principal diagnosis of aspiration
pneumonia--compared with a diagnosis of pneumococcal pneumonia--were dysphagia,
gastrostomy status, and staphylococcal pneumonia.
The question is whether this
increase in aspiration pneumonia arises from an actual increase in cases or is
merely an apparent increase resulting from selection pressure for the "aspiration
pneumonia" diagnostic code. Most Medicare payments for pneumonia hospitalizations
are covered by one of two sets of diagnosis-related groups (DRGs): "simple
pneumonia and pleurisy" and "respiratory infections and inflammation."
As the latter DRG covers pneumonias that may be particularly severe, the hospital
payment for these is generally higher than for "simple pneumonias."
Reporting a patient as having aspiration pneumonia instead of "pneumonia,
organism unspecified," shifts the DRG from the lower to the higher reimbursement,
which is obviously to the hospital's advantage.
If, on the other hand, Medicare
bills are pointing to a real increase in aspiration pneumonia, a second question
arises: What underlying processes are bringing about this increase? To find that
out, further research is needed, Dr. Baine noted.
must concentrate upon possible causal factors," he argued, "including
the possibility of previously unrecognized connections between some of these conditions
or their management and the risk of aspiration pneumonia."