Author Affiliations: Divisions of Adolescent/Young Adult Medicine (Dr Mansbach) and Urology (Dr Peters) and Clinical Research Program (Mr Forbes), Children’s Hospital Boston, Harvard Medical School, Boston, Mass.
To determine risk factors for testicular loss due to testicular torsion.
Design and Participants
Medical records of patients aged 1 to 25 years with a principal diagnosis of testicular torsion were extracted from the 1998 Nationwide Inpatient Sample. Population-based rates of testicular torsion and orchiectomy were determined. Logistic regression was used to create a predictive model for orchiectomy. For comparison, medical records of patients aged 1 to 25 years with a principal diagnosis of testicular neoplasm were extracted.
The sample comprised 436 participants. The estimated incidence of testicular torsion for males aged 1 to 25 years in the United States is 4.5 cases per 100 000 male subjects per year, and the estimated incidence of benign and malignant testicular tumors is 1.2 cases per 100 000. Of the estimated 2248 males diagnosed nationally in 1998 with testicular torsion, 762 (34%) had an orchiectomy. In the final multivariate model estimating the probability of orchiectomy, only age was significant.
For males aged 1 to 25 years, testicular torsion is more common than testicular tumors, and increasing age is the sole identifiable risk factor for orchiectomy. We suggest that health care professionals educate prepubertal male patients about testicular torsion and the necessity of seeking timely care to reduce the risk of orchiectomy and of possible subsequent reduced fertility.
Testicular torsion is a urologic emergency. There is approximately a 4- to 8-hour window from the onset of torsion symptoms until surgical intervention is required to save the affected testis.1 Delays in care may necessitate orchiectomy, which has been associated with reduced fertility.2 One study3 found that 57% of patients had low sperm counts a median of 5 years after unilateral testicular loss from torsion.
Providing the necessary medical and surgical services for a patient with testicular torsion requires 3 steps, namely, timely presentation, rapid diagnosis, and curative intervention. The surgical procedure performed would be orchiectomy for those patients with a nonviable testicle and septopexy for those with viable testes. One potential barrier to providing ideal care is delayed presentation. In fact, male subjects may be hesitant to seek medical attention for conditions involving their genitals, even for torsion.4 Fortunately, once a patient presents to a health care professional, the diagnosis of testicular torsion can usually be made from his history and physical examination. However, when the clinical diagnosis is uncertain, color Doppler ultrasonography is a helpful tool to differentiate torsion from other causes of an acutely painful scrotum.5
Further delays in diagnosis or treatment may be caused by individual patient factors. Appendicitis is a similar acute surgical condition in which delayed diagnosis or delayed surgery may lead to morbidity, specifically rupture of the appendix. In this condition, differences in the individual patient factors, including insurance status and race, have been associated with the risk of rupture of the appendix.6,7 The objectives of this study were to determine by using a national database if there are identifiable risk factors for testicular loss due to testicular torsion and to place the epidemiology of testicular torsion in the context of the more commonly discussed condition of testicular neoplasm.
The 1998 Nationwide Inpatient Sample (NIS) is part of the Healthcare Cost and Utilization Project, sponsored by the Agency for Healthcare Research and Quality.8 The NIS is a database of hospital inpatient stays, containing data from approximately 7 million hospital stays. The 1998 NIS contains all discharge data from 984 hospitals located in 22 states, approximating a 20% sample of US community hospitals. The overall goal for the NIS is to create a sample of hospitals that is generalizable to hospitals in the entire United States. The NIS data set includes a weight variable for each observation so that a weighted analysis can produce national estimates, with confidence intervals, of total cases and rates of procedures of interest. The Children’s Hospital Boston Institutional Review Board approved this study.
Medical records of patients aged 1 to 25 years with the principal diagnosis of testicular torsion (International Classification of Diseases, Ninth Revision, Clinical Modification [ICD-9-CM] code 608.2) in 1998 were extracted. The ICD-9-CM code 608.2 includes torsion of the testicle and torsion of the appendix testis and appendix epididymis. We compared the group of patients who received neither orchiectomy nor orchiopexy (n = 65) with the group who had a procedure (n = 436); the mean ages for the groups were 11.9 vs 15.0 years (P<.001). We excluded the 65 patients who did not have a surgical procedure, as these youth most likely had torsion of the appendix testis. All 436 patients who had a surgical procedure were included in the analysis.
Age-specific census estimates of the US male population were used to compute rates of testicular torsion and orchiectomy per 100 000 male subjects. The July 1998 US male population aged 1 to 25 years was extrapolated from census estimates for this population at July 1, 2000, and July 1, 2001. For comparison, medical records of patients aged 1 to 25 years with a principal diagnosis of testicular neoplasm (ICD-9-CM codes 186.9 and 222.0) were also extracted.
Statistical analyses were performed using SAS software version 9 (SAS Institute Inc, Cary, NC). In univariate analyses, t tests and Wilcoxon signed rank tests were used for continuous variables, and Fisher exact tests were used for categorical variables.
Analyses were conducted to determine the effect of different patient- and hospital-specific variables on the risk for orchiectomy. The patient-specific variables included age (treated categorically and continuously), race (white, black, or other), insurance status (Medicaid, self-pay, or private insurance), and annual household income (low income vs other, based on the median income of the patient’s ZIP code of residence). Hospital-specific variables included census region (4 levels) and hospital location (urban or rural, in which urban is within a census statistical metropolitan area).
Logistic regression was used to model orchiectomy rates controlling for the effects of hospital and patient covariates and to compute adjusted odds ratios. Because of the stratified and clustered sample design used by the NIS, the SAS Proc SurveyMeans was used to compute variances for totals and confidence intervals for torsion, orchiectomy, and testicular neoplasm. Logistic regressions accounted for clustering and stratification using SAS Proc SurveyLogistic.
Patients with missing covariate levels (<4% of the total) were included in logistic regression models by assigning them to the majority covariate level. The missing data from the race variable were analyzed 3 ways, namely, with the missing data treated as a separate covariate level, with the missing data removed from the analysis, and with the missing data assigned to the majority covariate level (white race). Race was not significantly associated with orchiectomy no matter how the missing values were assigned. As a result, in the final analyses, missing covariates were assigned to the majority covariate level.
The ICD-9-CM code 608.2 includes torsion of the testicle, appendix testis, and appendix epididymis. It is possible, therefore, that some patients, most likely the younger ones who had an orchiopexy, did not have torsion of the testicle but rather torsion of the appendix testis or appendix epididymis. If patients with torsion of the appendix testis or appendix epididymis had an orchiopexy, these misclassified patients would erroneously lower the percentage of younger males requiring orchiectomies. Therefore, a sensitivity analysis was performed to determine the potential effect of misclassification on our conclusions. Under the assumption that some of the youngest nonorchiectomy patients could be misclassified (ie, had an orchiopexy but not torsion of the testicle), random samples of 10%, 33%, and 50% of the nonorchiectomy patients in the youngest age category were removed, and the relationship between orchiectomy and age category (youngest vs oldest males) was reassessed. Although the correct proportion of the nonorchiectomy patients to be removed from the youngest age category is not known, we anticipate that much fewer than half of these patients, all of whom had a technically unnecessary surgical procedure, had torsion of the appendix epididymis or appendix testis.
The final sample comprised 436 eligible participants from 231 hospitals in 22 states. The number of torsion cases nationally, estimated using a weighted analysis of the data, was 2248 cases (95% confidence interval [CI], 1950-2547 cases). Using census results, we estimated the total male population aged 1 to 25 years in 1998 to be 50.25 million. Using these 2 results, the incidence of testicular torsion is 4.5 cases (95% CI, 3.9-5.1 cases) per 100 000 male subjects per year in the United States. Within the age range considered, testicular torsion is most common in males aged 10 to 19 years, with an incidence of 8.6 cases (95% CI, 7.1-10.1 cases) per 100 000 male subjects per year. For comparison, the database contained 120 patients with benign or malignant testicular tumors. Using a weighted analysis, the number of such cases nationally was estimated to be 621 cases (95% CI, 300-912 cases). Using the population estimate, the estimated incidence of benign and malignant testicular tumors is 1.2 cases (95% CI, 0.7-1.8 cases) per 100 000 male subjects per year, and the disorder is most common in males aged 16 to 24 years, with an incidence of 2.8 cases (95% CI, 1.4-4.2 cases) per 100 000 male subjects per year. Figure 1 shows that 86% of testicular torsion cases occur in males older than 10 years (median age, 15 years), while 82% of testicular cancer cases occur in males older than 15 years (median age, 20 years).
Cumulative number of patients with testicular torsion and with testicular cancer.
Of the 436 sample participants, 149 (34%) had an orchiectomy. Other characteristics of the sample are given in Table 1. Using the weighted data, of the estimated 2248 males diagnosed nationally as having testicular torsion in 1998, an estimated 762 (34%) had an orchiectomy. When age was grouped for descriptive purposes, the estimated percentage undergoing orchiectomy increased as age increased, namely, 19% among those aged 1 to 9 years, 33% among those aged 10 to 17 years, and 41% among those aged 18 to 25 years. In the weighted analysis, the rates were nearly the same, namely, 18% for those aged 1 to 9 years, 33% for those aged 10 to 17 years, and 41% for those aged 18 to 25 years. When the cutoff for the low annual household income group was changed from $25 000 to $35 000, the results were comparable.
The final multivariate model estimating the probability of having an orchiectomy included adjustment for race, insurance status, annual household income, census region, and hospital location (Table 2). In the final model, only age was significant. For a 1-year increase in age, the adjusted odds of having an orchiectomy increased by 1.08 (95% CI, 1.03-1.13), or an increase of 8% in the odds per year. For each 10-year increase in age, the odds of having an orchiectomy doubles (1.0810 = 2.2). Figure 2 shows the raw data with an overlay of the modeled relationship between age and the proportion of patients with testicular torsion having an orchiectomy. To show the raw data at a finer level of detail, the figure displays more age categories than were used in the analysis.
Estimated proportion of patients by age with testicular torsion having an orchiectomy. Error bars indicate 95% confidence intervals.
In the weighted analysis of the full data set, we observed orchiectomy rates among the youngest and oldest males of 18% and 41%, respectively (P<.001). We conducted a sensitivity analysis to evaluate the potential effect of misclassification on this result. With a random 10% of the males who did not undergo orchiectomy from the youngest age category removed, the estimated orchiectomy rates for the youngest and oldest age categories were 20% and 41%, respectively (P<.001). With a random 33% removed, the rates were 25% and 41%, respectively (P<.001). With a random 50% removed, the rates were 31% and 41%, respectively (P = .02). Therefore, the effect of age remained strong even with moderate to large misclassification of the youngest nonorchiectomy subjects.
Testicular torsion is a treatable urologic emergency, with an incidence that is 3.75 times greater than the incidence of testicular tumors. The frequency of testicular torsion increases before puberty and the sole identifiable risk factor for orchiectomy due to testicular torsion is increasing age. We identified no differences in orchiectomy rates for other patient factors such as race, insurance status, or hospital location.
For a male with testicular torsion to save his testicle, he must recognize the symptoms of torsion, access health care, and have a timely surgical procedure. Unfortunately, male subjects may be hesitant to seek medical attention for conditions involving their genitals, even for torsion.4,9 One study9 found that 85% of male respondents did not think that it was necessary to seek attention for testicular swelling and that 36% did not think that it was necessary to seek attention for testicular swelling and pain. Despite this knowledge gap, we are not aware of a formal recommendation or an adolescent health guideline advising health care providers to discuss the signs and symptoms of testicular torsion with their male patients.
Because the frequency of testicular torsion begins to increase when males are 10 years old, more than 5 years earlier than testicular tumors, it makes sense for health care professionals to educate prepubertal male patients about testicular disorders. Moreover, older adolescents have a documented knowledge deficit about testicular pathologic conditions10 and have fewer physician visits than preadolescents.11 To educate preadolescents about testicular disorders during health maintenance visits, health care professionals must not only believe that it is an important topic but also be comfortable discussing problems involving the testicle.12 The message to patients should be that scrotal pain, especially severe pain, requires immediate evaluation. In fact, any male in the peripubertal age group or older with scrotal pain should be presumed to have torsion until proven otherwise.
Although testicular salvage has been reported with prolonged torsion symptoms,13 delayed presentation and age affect orchiectomy rates. In a 10-year retrospective study14 of 30 patients, males younger than 18 years had delayed presentation and had more orchiectomies than those 18 years and older. In contrast, a more recent 9-year retrospective study15 of 44 patients demonstrated that males aged 21 to 34 years had more orchiectomies than those aged 8 to 20 years. Although these data by Cummings et al15 confirm that delays in presentation increase orchiectomy rates, there was no statistically significant age-related difference between the 2 age groups in the mean time to presentation. Because the time to presentation was similar between the 2 groups, the group aged 21 to 34 years was presumed to have a greater degree of spermatic cord twisting, causing the increased orchiectomy rate. Sessions et al16 reported greater median degrees of torsion in patients requiring orchiectomy (median, 540°) compared with patients with salvaged testicles (median 360°), but the range in both groups was identical and large (range, 180°-1080°). The national data in our study are consistent with the findings of the more recent study15 and identify a parallel between increasing age and increased orchiectomy rates.
Misdiagnosed testicular torsion resulting in loss of a testicle has legal implications, but the actual scope of malpractice claims related to torsion is difficult to determine.17 Most concerning for patients, and the basis of some malpractice claims, is the potential association between unilateral testicular loss due to testicular torsion and reduced fertility and sperm counts.2,3 Although the true pathogenesis of reduced fertility remains unproven, experimental data indicate that the contralateral intact testis may be harmed by antisperm antibodies18 or by increased germinal epithelial apoptosis.19 Other reports have suggested the presence of a congenital testicular dysplasia as the basis for reduced fertility in torsion.20,21 The conclusions about the role of congenital pathologic conditions, however, were based on the lack of relationship between the histological changes in the contralateral testis and the duration of torsion or the interval since torsion.20,21 Because this observation might indicate that reduced fertility in torsion is not preventable, preservation of as much testicular tissue as possible would seem to be a priority.
One limitation of this study is that these data are from 1998, but there have been no important changes in the management of patients with testicular torsion during this period.22,23 The database was not designed to address the possible explanations for the linear association between increasing age and the rate of orchiectomies. For example, there is no variable in the data set that permits adjustments for the duration of the torsion before presentation or for the degree of torsion. However, the lack of an explanation does not alter the message that males need to seek care quickly when they have scrotal pain. The study is also limited by the fact that the ICD-9-CM code 608.2 includes more diagnoses than torsion of the testicle, but our sensitivity analysis suggests that the major finding would remain significant even if half of the group aged 1 to 9 years did not have torsion of the testicle.
These data suggest that testicular torsion is more common than testicular neoplasm. Increasing age is a predictor of orchiectomy due to testicular torsion but not race, insurance status, or hospital location. We suggest that health care providers begin discussing testicular disorders, specifically testicular torsion, with prepubertal patients at the time of routine testicular examination. Moreover, national organizations may want to consider revising their male health guidelines to include earlier education about testicular health. Males should understand that acute or intermittent scrotal pain needs immediate medical evaluation and that delays may affect their fertility.
Correspondence: Jonathan M. Mansbach, MD, Division of Adolescent/Young Adult Medicine, Children’s Hospital Boston, Harvard Medical School, 300 Longwood Ave, Boston, MA 02115 (Jonathan.Mansbach@childrens.harvard.edu).
Previous Presentation: This study was presented in part at the 2002 Annual Meeting of the Society for Adolescent Medicine; March 24, 2004; St Louis, Mo.
Accepted for Publication: June 6, 2005.
Funding/Support: This study was supported by a grant from the Novack Family Foundation, Boston (Dr Mansbach).
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