The Workplace Impact of Acute Exacerbations of Chronic Bronchitis (AECB); A Literature Review

Abstract

Acute exacerbations of chronic bronchitis (AECB) are known to have a substantial economic burden in terms of medical care costs. The objective of this study was to assess workplace‐based costs associated with AECB, including absenteeism and decreased productivity, based on a review of published literature. A secondary goal was to identify factors related to workplace‐based costs in AECB. A literature search was conducted to identify relevant articles assessing one or more aspects of work loss or workplace costs among patients with chronic bronchitis. A review of the identified literature indicates that patients with chronic bronchitis had more days off work; patients whose exacerbations were treated were less likely to have additional exacerbations and had comparatively less work loss. Findings suggest that clinical outcomes and workplace costs are related. While this relationship is clearer in terms of work loss, further exploration is needed to assess decreased productivity and to evaluate this relationship using objective indicators of absenteeism and productivity rather than recall.

• Chronic bronchitis
• COPD
• Exacerbation
• Productivity
• Absenteeism

Introduction

Acute exacerbation of chronic bronchitis (AECB) is acute inflammation of the bronchial airways in the presence of underlying chronic bronchitis [[1]]. AECB is generally accompanied by bacterial infections; standard treatment for AECB is antibiotics [[2]]. Approximately 13 million persons in the United States (almost 5% of the adult population) have chronic bronchitis and experience acute exacerbations [[3]][[4]].

There is extensive literature regarding the economic impact of chronic obstructive pulmonary disease (COPD) treatment in terms of medical care costs. Studies of medical care costs for treatment of AECB, a subset of the overall cost of COPD literature, have been recently reviewed [[5]]. However, the economic burden of medical conditions goes beyond direct costs (i.e., costs for medical resource utilization). Recently, more studies have emphasized indirect costs, including workplace‐based costs. Workplace costs result from increased workplace absenteeism and/or decreased workplace productivity among patients with a specific medical condition or risk factor. In many cases, workplace costs exceed direct medical costs; based on 1993 estimates, the direct medical care cost of chronic obstructive pulmonary disease (COPD, including chronic bronchitis and emphysema) in the U.S. was $7 billion, while lost productivity accounted for $8 billion [[6]]. An estimate of the 1994 productivity loss to COPD is even greater, $9.9 billion [[7]].

It is likely that workplace costs associated with AECB, an acute event occuring episodically for COPD patients, may be reduced by appropriate medical management. In order to assess the potential for these cost reductions, this manuscript was developed to review the available literature regarding the impact of AECB on workplace costs. Studies evaluating workplace absenteeism and/or workplace productivity among this patient population are reviewed. We also summarize literature assessing factors related to workplace costs of AECB, including the role of different occupations.a

Materials and Methods

A MEDLINE literature search was conducted to identify articles with the MeSH headings COPD, chronic bronchitis, or emphysema, and exacerbation, and productivity, sick leave or absenteeism in addition to related search terms automatically prompted by the search engine. Articles were selected for review based on disease‐specific information related to work loss or workplace costs. Reference lists of identified articles were also reviewed for additional relevant information. All identified articles providing information on workplace costs of AECB were included in this review. As noted above, articles focusing only on medical care treatment costs for AECB have been recently reviewed and are not included in this report [[5]]. Studies providing information on the workplace costs associated with acute respiratory conditions or chronic respiratory diseases overall without specific information on AECB (e.g., Ref. [[7]]) were also excluded. Further, the impact of occupational exposures causing COPD, while an important topic, is beyond the scope of this review of the workplace economic impacts of AECB. Thus, articles focusing only on the relationship between occupational exposures and COPD without information on workplace costs are also not included. Readers interested in this topic are referred to the recent article by Trupin et al. [[8]].

Results

Impact of Acute Exacerbations of Chronic Bronchitis on Workplace Absenteeism

Francis and Spicer [[9]] evaluated work days lost based on a randomized, double blind control trial of 252 patients in Great Britain. The trial included three treatment groups: tetracycline, 250 mg BID; penicillin V, 312 mg BID; and placebo. All patients were working males aged 30–65 who had suffered from “winter cough” with sputum for the past 3 years, during which time they were off work twice due to bronchitis with purulent sputum. Treatment occurred from January 5 to April 30, 1959. Outcomes included number and duration of “bronchitic exacerbations and pneumonic episodes” in each group, average number of working days lost as a result, cost to the patient due to time off work, and cost to the government from paid sickness benefits.

A total of 26 patients were excluded from the analysis due to unemployment throughout the period or lack of adequate records. Analysis of the 226 remaining patients revealed that both penicillin and tetracycline reduced the number of work days lost due to AECB or pneumonic episodes by approximately half compared to the control group. The average days off work during the study period were 6.8 for the penicillin group, 7.5 for the tetracycline group, and 14.2 for the control group. The average duration of AECB episodes (in days) per patient was 9.0 for the penicillin group, 11.5 for the tetracycline group, 21.3 for the control group. Results for treatment with penicillin versus tetracycline were not significantly different.

Alderson [[10]] investigated “periods of incapacity” that resulted in missing work for more than four days during a year among 620,457 men in Great Britain. Among the study participants, 28% experienced an incapacity for work lasting longer than 4 days due to all causes at some time during the year. Bronchitis was among the conditions resulting in the highest rate of workplace incapacity, at 3.7 per 100 men. The rate of workplace incapacity due to bronchitis was also evaluated by occupational class. In the professional and intermediate occupational classes, the workplace incapacity rate due to bronchitis was 1.5 per 100, compared to 3.5 per 100 in the skilled occupational class, 4.3 per 100 in the partly skilled class, and 5.7 per 100 in the unskilled class.

Lops et al. [[11]] evaluated the impact of chronic bronchitis among workers at an Italian foundry. Thirty workers with chronic bronchitis were compared to the remaining 4,800 workers from the same firm. Data were collected over a three month period (October to December) in 1969. Workers with chronic bronchitis averaged 12.2 days of work lost during the three month study period, while the control group had an average of 4.1 workdays lost over this period. Over the same three month period in the following year (1970), workers with chronic bronchitis were treated with doxycycline (single dose of 200 mg during the first 24 hours of therapy followed by 100 mg for each of 20 days). The treated workers with chronic bronchitis experienced an average of 5.3 days of lost work over this period, a reduction of 6.9 work loss days compared to the untreated period. Workers in the control group averaged 3.2 work loss days over the three month period.

Grandjean et al. [[12]] performed a cost‐effectiveness analysis of treatment for AECB from a payer's point of view in the Swiss health care system. Their study design was based on a retrospective meta‐analysis of 9 published prospective double‐blind placebo‐controlled studies of oral N‐acetylcysteine (NAC). The indirect costs evaluated were based only on working days lost. The average age of the patients in these trials ranged from 51 to 63. Combining the results of the trials yielded overall samples sizes of 1025 for the NAC group and 1073 for the placebo group. The pooled studies were statistically homogeneous. The difference between groups in the percentage of patients per month with AECB episodes was statistically significant (p < 0.001), with 16.1% having AECB among those receiving NAC and 25.5% having AECB among those receiving placebo. The mean number of AECB episodes per patient in a six month period was 0.97 for NAC patients and 1.53 in the placebo group, corresponding to a 37% reduction in episodes (p < 0.001).

Five of the nine evaluated studies reported on sick leave. The pooled results indicated 9.7 sick days per placebo patient over 6 months (5.3% of workdays), while the NAC group experienced 6.5 sick days per patient per 6 months (3.6% of workdays). This difference (32.5% fewer sick days) was statistically significant. To evaluate costs, the authors used the Swiss fee system for procedures and medications and presented monetary values in Swiss Francs (CHF). Sick leave costs were 79 CHF for compliant patients treated with NAC, 388 CHF for non‐compliant patients treated with NAC, and 455 CHF for placebo‐treated patients. On average, NAC treatment prevented 0.6–0.7 AECB episodes over a period of 6 months, resulting in savings of direct costs of approximately 175 CHF per patient and indirect costs of approximately 545 CHF per patient.

Halpern et al. [[13]] conducted an economic analysis based on data from the Gemifloxacin Long‐term Outcomes in Bronchitis Exacerbations (GLOBE) study. This prospective double‐blind, controlled, health outcomes study compared health economic and clinical outcomes after randomized treatment with either oral gemifloxacin or oral clarithromycin for AECB. This study included 386 patients at 46 centers in the US and 52 patients at 10 centers in Canada. Patients in the study were followed for up to 26 weeks, and self‐reported time off of work due to AECB episodes. Economic values were also assigned to days lost from work to estimate indirect costs using age‐ and gender‐specific daily wage rates.

Compared with clarithromycin, gemifloxacin treatment resulted in significantly more patients without AECB recurrence requiring antibiotic treatment after 26 weeks (73.8% [158/214] vs. 63.8% [143/224], p = 0.024). Patients who received gemifloxacin had slightly fewer days off work, 2.0 (± 10.1), compared with 2.2 (± 7.4) days for those taking clarithromycin. There was a similar mean work cost per patient treated with gemifloxacin vs. clarithromycin over the 26 week period of the study ($263 vs. $270, respectively). Including direct costs and lost productivity costs, the total mean per‐patient costs were $1,468 vs. $1,797 for gemifloxacin vs. clarithromycin, respectively. This corresponds to a mean societal saving with gemifloxacin of $329 over the 26 week study period.

Impact of Acute Exacerbations of Chronic Bronchitis on Workplace Productivity

Li‐McLeod and Perfetto [[14]] evaluated the impact of two antibiotics, moxifloxacin and levofloxacin, on absenteeism and workplace productivity due to chronic bronchitis. Changes in absenteeism and productivity were assessed over two time periods: 1) while undergoing medication therapy, and 2) post‐therapy. Information was collected during these time periods on hours of work missed because of acute exacerbation of chronic bronchitis (AECB), hours of work missed for reasons other than AECB, number of hours worked during the study period, and a rating of the effect of AECB while working.

There were no statistically significant differences between the two medications in terms of workplace productivity or absenteeism while taking the drug or post‐therapy. Participants in the moxifloxacin group reported missing 5.2 ± 9.8 hours of work due to AECB (n = 91) while the levofloxacin group (n = 101) reported 7.6 ± 12.9 hours of work missed. The average cost due to lost productivity for moxifloxacin was $830 while the levofloxacin group experienced productivity loss of $969 per person per AECB episode. Although these differences were not statistically significant, the moxifloxacin group experienced both a higher overall work‐related productivity and fewer hours of absenteeism than those taking levofloxacin. Patients taking moxifloxacin also believed that they worked at a higher percentage of their abilities than did those who were taking levofloxacin [[14]].

Factors Related to Workplace Costs of Acute Exacerbations of Chronic Bronchitis

A number of reports have linked chronic bronchitis with occupational and environmental exposures [[15]]. More than 35 years ago, the British Medical Research Council [[16]] published committee findings on the relationship between chronic bronchitis and occupation, with particular reference to the coal mining industry. The committee concluded that chronic bronchitis does not have any clinically different characteristics based on occupation. Further, chronic bronchitis cannot be attributed to any particular environmental factor, including occupational factors. Workplace incapacity from bronchitis was reported to be greatest among heavy, non‐agricultural occupations including mining, furnace, forge, foundry, rolling mill, gas, coke, and chemical workers. There does appear to be an association between occupation and mortality due to chronic bronchitis; for example, the lowest bronchitis mortality rate was observed for agricultural workers and the highest rate for miners. However, this may in part reflect a bias towards listing “miner” as the death certificate occupation even for individuals who no longer work as miners. An editorial written in the same issue of the British Medical Journal as the Medical Research Council's report indicates that bronchitis accounts for nearly 40 million lost working days per year out of a total of 400 million working days lost per year in Great Britain [[17]].

Clark et al. [[18]] used structured in‐person interviews to gain knowledge about factors that lead to unemployment in those suffering from chronic bronchitis in Great Britain. Both employed and unemployed males (n = 93) aged 40–64 years were evaluated in this study. Several questionnaires were used to gather demographic, medical, and personal information. Information regarding work status and efforts to find work were also gathered.

These researchers found that unemployment was associated with a combination of factors, including the participant's skills, family support, motivation, and severity of disease. Additional factors affecting unemployment were related to the job, such as travel accommodations, working conditions, and pay. Some of the men in the study approached their employers for help in finding a more suitable job given their disability, but this often resulted in a cut in pay. Of the employed men participating in this study, 12 missed less than 1 week or work, 44 missed between 1 and 8 weeks, and 44 missed more than 8 weeks.

Discussion

Multiple studies performed over several decades indicate that chronic bronchitis is associated with substantial workplace costs. A number of studies have demonstrated increased workplace absenteeism among chronic bronchitis patients; fewer studies have evaluated workplace productivity among these patients. However, based on the reviewed studies, there are clear links between clinical outcomes and workplace costs among AECB patients. First, treatments that decrease the duration of AECB episodes can decrease workloss. As presented by Francis and Spicer [[9]], penicillin treatment had the greatest impact on decreasing both the duration of AECB and the amount of work loss due to AECB. Similarly, treatments that decrease the rate of AECB are also associated with decreased work loss. For example, Grandjean et al. [[12]] reported that NAC treatment significantly decreased the rate of AECB episodes; NAC patients also experienced substantial decreases in work loss as compared to placebo‐treated patients.

These findings suggest that optimal therapy for AECB, in addition to improving patient health and decreasing health care costs, will also decrease workplace costs. Pechere and Lacey [[19]] comment that patients with AECB may have poor treatment compliance and higher rates of antibiotic resistance, increasing the likelihood of treatment failure and associated costs. They thus recommend use of antibiotics that include short duration of treatment, broad antibacterial spectra, and once daily dosing. This will likely improve outcomes and reduct costs resulting from treatment failure for AECB, including workplace costs.

Future studies should evaluate the impact of AECB treatments on workplace costs using a more quantitative methodology. Perfetto et al. [[20]] recommended that patient‐reported outcomes of work loss and productivity level at work be included as endpoints in studies of AECB. However, most of the studies reviewed in this manuscript, as well as most studies evaluating disease‐related workplace absenteeism in general, rely on self‐reported data for days of work missed. Patients may have recall biased in providing these data, or may reduce or inflate the days reported based on their perceptions of their employers acceptance of this condition. Use of recorded absenteeism data from employers will provide more robust information.

In addition, there is almost no information on the impact of AECB on workplace productivity. Presenteeism, that is, impaired performance while at work, may result in even greater costs than absenteeism. In most studies that do evaluate the impact of medical conditions or risk factors on workplace productivity, these data are also generally based on self‐reporting and are subject to multiple biases. Use of either objective workplace productivity measures or a validated subjective productivity assessment instrument would provide more valid results. The Health and Work Questionnaire (HWQ), an instrument for subjectively evaluating workplace productivity, has recently been partially validated against objective productivity measures among a population of current and former smokers [[21]]. Use of the HWQ or other robust measures will be important in providing evidence of the workplace burden of AECB to medical care decision makers.

To comprehensively assess the workplace costs of AECB, it will be important to perform a prospective study. Ideally, participants in the study (individuals with diagnosed emphysema or chronic bronchitis) will be randomized into two or more AECB treatment groups, and both participants and health care providers will be blinded to treatment group status. Each group will receive a different therapy at the onset of AECB symptoms as determined a priori in the study protocol. Data collection will include clinical information related to AECB (e.g., type, severity, and duration of symptoms) as well as objective measures of absenteeism and both objective and subjective measures of decreased productivity on a daily basis. These results will provide detailed information on the link between AECB clinical characteristics and workplace costs, and will provide additional evidence regarding the importance of appropriate treatment for AECB.

Acknowledgments

This work was funded by a research contract from GlaxoSmithKline.

Notes

^aThis work was funded by a research contract from GlaxoSmithKline.