Bohm, Michele K. MPH; Gift, Thomas L. PHD; Tao, Guoyu PHD
From the Division of STD Prevention, National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, Centers for Disease Control and Prevention, Atlanta, Georgia
Correspondence: Michele K. Bohm, MPH, Centers for Disease Control and Prevention, 1600 Clifton Rd. NE, MS D28, Atlanta, GA 30329-4018. E-mail: firstname.lastname@example.org.
Received for publication June 16, 2008, and accepted March 1, 2009.
Epididymitis is characterized by unilateral pain and swelling in the scrotum, testicle, or epididymis, and is usually accompanied by urethritis.1,2 This condition may occur as a result of infection, systemic disease, or a physiological condition.2 Experts believe that the syndrome of acute epididymitis among sexually active males under the age of 35 most often results from untreated sexually transmitted infections, especially Chlamydia trachomatis and Neisseria gonorrhoeae.1,3 Chronic epididymitis, although more rare, also occurs in this young age group, and may or may not be associated with persistent infections (untreated infections or relapse following treatment failure) or reinfections (a new infection caused by the same or different organism). Some cases are not associated with an identified pathogen at all. The diagnosis and management of these conditions have improved in recent years, which has led to some decrease in morbidity and possibly to prevention of recurrences.4 Nonetheless, the literature on acute and chronic epididymitis is limited, and our understanding of its etiology and epidemiology is still incomplete. Knowledge of patterns of recurrence could be used to further enhance rescreening strategies for this syndrome.
Efforts to prevent bacterial sexually transmitted disease (STD)-related sequelae are focused heavily on women because pelvic inflammatory disease, chronic pelvic pain, ectopic pregnancy, and infertility impose huge financial, societal, and personal costs. Chlamydia screening, for example, is recommended annually for all young sexually active women by the Centers for Disease Control and Prevention, the US Preventive Services Task Force, and many professional medical organizations.5–7 The high prevalence of asymptomatic infection in women gives impetus to prevention initiatives because screening can detect silent infections and potentially avert future costs. Male gonorrhea and chlamydial infections are more frequently symptomatic, and routine screening is not universally recommended though asymptomatic infections can progress to epididymitis.8 Male screening is typically only practiced in high-risk venues, such as STD clinics and incarceration facilities, and among high-risk groups, such as men who have sex with men and military recruits. Although direct medical costs for epididymitis are lower than costs associated with STD sequelae in women, epididymitis can still have serious implications and may lead to male infertility or chronic pain and inflammation.9–11
Reinfection rates after treatment for chlamydia or gonorrhea are high,12,13 further elevating the risk for epididymitis.4 It is possible that biologic susceptibility or behavioral risk factors could predispose some men to multiple episodes of epididymitis, as is the case with recurrent STDs. We sought to expand our understanding of the epidemiologic profile of epididymitis by determining whether a pattern among single and multiple insurance claims would emerge among men diagnosed with this syndrome. A tendency toward multiple claims of epididymitis could indicate a need for more timely follow-up care, reevaluation, or monitoring among those previously diagnosed with the condition.
To determine the proportion of men with single and multiple claims for epididymitis, we utilized Medstat’s MarketScan Database, which contains insurance claims for over 5 million privately-insured US enrollees annually. The data are obtained from a regionally distributed convenience sample of Americans enrolled in employer-sponsored health plans.14 We analyzed data from 2001 to 2004 and identified our study population as male enrollees with continuous coverage and between the ages of 14 and 35 at any point during this time. Selecting only those with continuous coverage allowed us to follow a defined cohort longitudinally over 4 years. By restricting the cohort to this age group, we hoped to capture those patients most likely to have epididymitis associated with chlamydia and gonorrhea.
We reviewed inpatient and outpatient claims records for this population and selected those with either a primary or secondary diagnosis of epididymitis or orchitis as indicated by International Classification of Disease, Ninth Revision, Clinical Modification (ICD-9-CM) codes.15 The coding system groups epididymitis and orchitis together; there is no specific code for orchitis and as such, we were unable to differentiate orchitis claims from epididymitis claims. Specifically, we included codes 604.0, 604.90, and 604.99, which indicate orchitis, epididymitis, and epididymoorchitis with and without abscess. We did not include 604.91, which is predominantly used as a secondary diagnosis to an underlying disease. We excluded 072.0 and 016.5, which are used for epididymitis caused by mumps and tuberculosis, respectively, but did include 098.13 and 098.33, which indicate gonococcal epididymoorchitis.15 We then determined the number of single and multiple claims of epididymitis among the men in our study population. For those enrollees with 2 or more claims, we defined a second (multiple) claim of epididymitis as those claims occurring more than 60 days after the date of care indicated on the previous claim.9 Claims with intervals of 60 days or less between them were grouped as a single claim. In this way, claims representing follow-up visits for a single diagnosis would not be reflected as multiple diagnoses of epididymitis. A previous study found minimal variation in the number of episodes of epididymitis defined by a given number of outpatient visits when comparing intervisit gaps of both 45 and 90 days to 60 days.9
MarketScan National Weights were applied to the data when calculating the overall rate of epididymitis diagnoses in the study population and the geographic distribution of these patients. These weights were constructed using the Medical Expenditure Panel Survey,16 and provide estimates of the number of people in the United States with employer-sponsored private health insurance. The weights account for differences in geographic region, age, gender, metropolitan statistical area, and insurance policy holder status. Weighted statistics can be calculated for the total population or when stratifying by particular weight categories. Applying these weights to the Medstat data make the results generalizable to the US population enrolled in employer-sponsored health plans.14 Race and ethnicity data are not available in Medstat.
Of 316,418 eligible men between the ages of 14 and 35 with continuous enrollment that comprised our study population, 4636 had at least one claim for epididymitis (1.6% weighted) during the 4-year study period. More patients were in the 31 to 35 age group than any other age group (Table 1). In addition, more patients resided in the South region of the United States (where STD rates are consistently among the highest in the country) than in any other region. Collectively, these patients submitted a total of 5310 claims for epididymitis from 2001 through 2004. Although a majority of patients with a diagnosis of epididymitis had only one claim during the study period, 11.4% (526/4636) had multiple claims (Table 2). The data in Table 2 show an increasing tendency for multiple claims as the number of claims increases, which could indicate recurrence or a chronic condition. The median interval between episodes was 194 days (interquartile range, 109–376 days).
Several limitations of this analysis warrant discussion. The strength of this study lies in the claims database and the millions of persons for which it has information. However, the data cannot show whether a given case of epididymitis resulted from an untreated STD. This limitation would persist even if we could perform medical chart reviews because epididymitis mostly occurs with undiagnosed and untreated bacterial STDs.4 Further, there are many causes of epididymitis, and the specificity of our case definition was bound by ICD-9-CM codes as well as the accuracy of the coding process (e.g., cases could be coded using a relatively nonspecific ICD-9-CM such as 608.9 for unspecified male genital disorders). Similarly, it was impossible to completely distinguish between multiple claims for several diagnoses of epididymitis from one lengthy chronic case. However, the syndrome of chronic epididymitis is not well characterized, and these results could still inform our understanding of the relationship or progression between multiple acute infections and chronic conditions. Also, by restricting our data to a specific study period, we inevitably failed to capture some multiple claims. Restricting our analysis to only men who had continuous enrollment may also have introduced selection bias, but was done to enable examination of multiple claims for the same individual over a long period of time. The Medstat population in general, and our study population of continuously enrolled males in particular, represent a broad category of individuals with likely lower STD risk factors than those individuals for whom we have more data, such as those attending family planning clinics, visiting STD clinics, incarcerated in jails and prisons, and serving in the military. Although our results are likely representative of privately-insured patients enrolled in employer-sponsored health plans, they cannot be generalized to other populations, including those receiving publicly-funded healthcare, the uninsured, or those who self-pay for care.
Although it was not the intent of this analysis to link claims of epididymitis to a specific STD, our results on the geographic distribution of epididymitis mirror the geographic distributions of STDs wherein the highest rates are in the South. STD rates are known to be disproportionately high among blacks in the United States. The South has a high proportion of blacks, which partially explains the observed geographic distribution of STDs and which may also be reflected in our results on epididymitis.
Our finding that more patients with epididymitis were between the ages of 31 and 35 years than in other age groups deserves further investigation. STD incidence rates typically peak in younger age groups. It may be that older men are more likely to progress to epididymitis after an infection, or that the syndrome is less likely to be related to an untreated STD in older age groups as the commonly held view indicates. Additional research could better substantiate this view. Previous studies showing the association between STDs and epididymitis in men under the age of 35 mostly involved small numbers of men within very specific clinical settings, which is in direct contrast to the data we present.
The weighted epididymitis diagnosis rate of 1600 per 100,000 enrollees for this population was calculated over a 4-year period of observation. The data revealed that the proportion of men diagnosed with epididymitis who had subsequent claims increased as the number of claims increased. These results could be used to determine the value of routinely screening young men previously diagnosed with epididymitis for chlamydia and gonorrhea as a part of follow-up care management. The claims data could provide a range for cost-effectiveness models, from all claims after a 60-day gap representing a recurrence, to all claims for one person representing a single episode of chronic epididymitis. Even if all multiple claims represented chronic epididymitis, it still indicates that for some men, epididymitis is a problem of long duration. For an individual at risk for recurrence, retesting (or testing) for STDs at an optimal time interval after diagnosis of epididymitis might prevent another episode of epididymitis. An optimal time interval for rescreening should occur well before the usual onset of a recurrent episode of epididymitis. Our results of the median interval between claims suggest rescreening should occur within 3 to 4 months of diagnosis. Additional research that incorporates medical records data are needed to establish a more precise interval and to better ascertain if recurrence is a marker for chronic epididymitis.
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