A cheaper, faster way to resolve chronic cough: "presumed diagnosis" strategy offers early treatment, a cost savings, and >90% treatment response

Journal of Family Practice, August, 2007 by Jaechun Lee, Miok Kim, Jeong Hong Kim, Young Ree Kim, Sohyung Kim, Yeol Kim

Practice recommendations

* When evaluating chronic cough, consider a trial of therapy aimed at the most likely presumptive diagnosis for your locality.

* In developing algorithms such as ours, take into account your experiences, patient characteristics, and the available medical equipment.

At the insistence of her family, a woman comes to you complaining of a cough that has lasted several weeks. Many experts would urge a thorough diagnostic investigation, justifying this action with a presumed shorter course of treatment. But is an involved work-up really necessary? Would a quicker, less expensive approach serve the patient just as well? We designed our study to answer these questions.

* "Test all, then treat" is expensive

In the management of patients with chronic cough, most algorithms have advocated the approach of "test all, then treat." (1-6) This is an expensive approach and one that delays relief for the patient, though a confirmative diagnosis may decrease the overall duration of treatment. In most cases, however, this approach may be unnecessary. And because few of the underlying disorders are acutely debilitating or rapidly progressive, even misdiagnosis and resultant inappropriate treatment pose little risk to patients.

The less common approach is a sequence of trial-and-error treatments based on a presumptive hierarchy of possible diagnoses. (6) The advantage with this strategy is a 3- to 5-fold cost savings. (6) And we suspected that the associated length of treatment would be acceptable.

We proposed that the management of patients with chronic cough begin with a presumptive diagnosis, thus simplifying the initial evaluation, keeping costs low, and offering earlier treatment.

We developed an algorithm for the treatment of patients with chronic cough that relies on minimal diagnostic investigations, regardless of the confirmed diagnosis. We evaluated our approach from the perspectives of the presumptive diagnosis and the therapeutic response period.

* Methods

Treatment algorithm reflects experience and local resources

Initially, we designed the algorithm to follow findings in the literature on the treatment of patients with chronic cough. We then simplified and modified the algorithm to reflect the experiences of doctors from the pulmonology clinic in our hospital, and to take into account local patient characteristics and available medical equipment and resources.

Subjects were otherwise healthy

Between January 1 and December 31, 2005, at the internal medicine clinic of Cheju National University Hospital, we enrolled 378 patients whose chief complaint was cough persisting for more than 4 weeks and who had no abnormalities detected on auscultation by a physician, chest radiography (posterior-anterior view and left lateral view), or complete blood cell counts. Each patient had a complete blood count to detect anemia, hematologic disorders, or inflammatory conditions. Current users of angiotensin-converting enzyme (ACE) inhibitors were excluded.

All of the patients we enrolled were adults living in Jeju, Korea, and the mean age was 51 years. One hundred eighty-six (49%) were men. The median reported cough duration was 2 months (range, 1-36 months) (TABLE 1).

We instructed the patients on our algorithmic approach to treating chronic cough and encouraged them to follow the algorithm through to telephone notification of the next visit.

How we determined treatment outcomes

Patients graded their cough severity subjectively at each visit using a visual analogue scale (VAS) from 1 (no cough at all) to 10 (cough severity same as that remembered during first visit to the clinic). We recorded their reports on a questionnaire.

Successful responders were patients who reported a subjective grade of cough severity less than 3. Partial responders and nonresponders were defined, respectively, as those reporting VAS scores from 3 to 6 and more than 6.

We defined the response period as the number of days from enrollment until the next visit in which the patient first reported a VAS score of cough severity less than 3.

Algorithm: Addressing the 3 most common causes of chronic cough

1. Postnasal drip syndrome. Patients first underwent a rhinoscopic examination (FIGURE). When clinicians detected redness or abnormal discharge on the nasal mucosa, they prescribed a 5-day course of antihistamine (10 mg/day ebastine [Ebastel] orally), pseudoephedrine (30 mg 3 times daily, orally), and intranasal corticosteroid (triamcinolone acetonide [Nasacort] 110 mcg twice daily intranasally). Patients without symptoms of rhinitis were referred to the next diagnostic phase.

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With completion of the prescribed medication 5 days after the first visit, we graded the severity of cough by questionnaire. Patients in the successful and partial responder categories received a presumptive diagnosis of postnasal drip syndrome, and we asked them to continue using the medication for at least 2 weeks. We had each nonresponder stop the medication.

2. Asthma syndrome. Partial responder and nonresponder patients entered the next diagnostic phase: a methacholine bronchial provocation test (MPT) (7) and eosinophil count with induced sputum by hypertonic saline (3% NaCl). (8) We defined a positive MPT result as <10 mg/ mL of methacholine causing a 20% fall in FE[V.sub.1] from baseline (P[C.sub.20]). Patients with more than 3% eosinophils in the induced sputum specimen or with a positive MPT received a 1-week prescription for inhaled budesonide 160 mcg twice daily and inhaled formoterol (Symbicort) 4.5 mcg twice daily. Patients who did not exhibit these asthma indicators were referred to the next step. At the next visit, we again graded the severity of cough. Patients in the successful and partial responder categories received a presumptive diagnosis of asthma syndrome. We asked successful and partial responders to continue the medication for at least 2 weeks. Those classed as nonresponders were asked to stop their medication. We referred all patients with positive MPT test results to a special clinic for asthma, regardless of responses to this therapeutic trial or eosinophil count in the induced sputum.