American Journal of Epidemiology Advance Access originally published online on March 20, 2007
American Journal of Epidemiology 2007 165(10):1154-1161; doi:10.1093/aje/kwm011
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ORIGINAL CONTRIBUTIONS |
Risk Factors for Inguinal Hernia among Adults in the US Population
1 Social & Scientific Systems, Inc., Silver Spring, MD
2 National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD
Correspondence to Dr. Constance E. Ruhl, Social & Scientific Systems, Inc., 8757 Georgia Avenue, 12th floor, Silver Spring, MD 20910 (e-mail: cruhl{at}s-3.com).
Received for publication July 7, 2006. Accepted for publication November 14, 2006.
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ABSTRACT |
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 TOP ABSTRACT INTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONReferences |
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The authors examined risk factors for incident inguinal hernia among US adults (5,316 men and 8,136 women) participating in the First National Health and Nutrition Examination Survey (1971–1975) who were followed through 1992–1993 for a hospital (International Classification of Diseases, Ninth Revision, Clinical Modification, code 550) or physician diagnosis of inguinal hernia. Ninety-six percent of the baseline cohort was recontacted, with a median follow-up of 18.2 years (range, 0.02–22.1 years). Because the cumulative incidence of inguinal hernia was higher among men (13.9%) than among women (2.1%), more detailed analyses were conducted in men. Among men in multivariate analysis, a higher incidence (p < 0.05) of inguinal hernia was associated with an age of 40–59 years (hazard ratio (HR) = 2.2, 95% confidence interval (CI): 1.7, 2.8), an age of 60–74 years (HR = 2.8, 95% CI: 2.2, 3.6), and hiatal hernia (HR = 1.8, 95% CI: 1.2, 2.7), while Black race (HR = 0.58, 95% CI: 0.42, 0.79), being overweight (HR = 0.79, 95% CI: 0.66, 0.95), and obesity (HR = 0.51, 95% CI: 0.36, 0.71) were associated with a lower incidence. Among women, older age, rural residence, greater height, chronic cough, and umbilical hernia were associated with inguinal hernia. In the United States, inguinal hernias are common among men, especially with aging. The lower risk among heavier men was unexpected and bears further study.
adult; hernia, inguinal; prospective studies; risk factors; United States
Abbreviations: CI, confidence interval; HR, hazard ratio; NHANES I, First National Health and Nutrition Examination Survey
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INTRODUCTION |
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TOPABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONReferences |
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Inguinal hernias are the most common form of abdominal wall hernias. The incidence of inguinal hernia is unknown, but about 500,000 cases come to medical attention each year (1). No recent data on the prevalence of inguinal hernia in the United States based on physical examination are available. In international and US surveys conducted 20 or more years ago, the prevalence of non-surgically-treated inguinal hernia among men was 5–7 percent, and a similar number of men had a history of hernia repair (1). Inguinal hernias are much more common among men than among women. They may also be more common among Whites and older adults (1).
The health effects of inguinal hernia are considerable. In 1989–1990, there were an estimated 1.65 million annual first-listed ambulatory care visits for inguinal hernia in the United States (1). Today most herniorrhaphies are performed as an outpatient procedure. Before this trend began, there were over 600,000 overnight hospital stays per year for inguinal hernia in the United States (1). Furthermore, it has been estimated that in the United States, hernias have resulted in significant limitation of activity for approximately 400,000 persons, and the number of days of work lost is higher than for any other chronic digestive condition (1). Complications of inguinal hernia include incarceration, bowel obstruction, and bowel strangulation (which is potentially fatal), with the greatest risk being found among older persons. Although risk of death is small, hernia was listed as the underlying cause of death for 1,595 US deaths in 2002 (2).
Despite the common occurrence and clinical significance of inguinal hernia, only a few studies have investigated risk factors for inguinal hernia (3–7). Two studies found increased risk with strenuous exertion (4, 5). Interestingly, being overweight was associated with lower risk in two studies (3, 6). Associations with inguinal hernia were found in individual studies for varicose veins (3), history of hemorrhoids (3), smoking (8), and hiatal hernia (7). To our knowledge, risk factors for inguinal hernia have not been evaluated in a prospective cohort study or in any US population. Therefore, we examined the relation between potential risk factors and incident inguinal hernia in the First National Health and Nutrition Examination Survey (NHANES I) and its follow-up study, a large, population-based US prospective study.
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MATERIALS AND METHODS |
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TOPABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONReferences |
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NHANES I
Conducted between 1971 and 1975, NHANES I included interview, examination, and laboratory data collected from a national probability sample of the civilian, noninstitutionalized US population (9, 10). Of 20,729 sampled persons, 14,407 (70 percent) underwent a medical examination (11). At the NHANES I interview, participants were asked about nonrecreational activity (inactive, moderately active, very active) and recreational activity (little or no exercise, moderate exercise, much exercise); constipation and frequency of bowel movements; and whether they had ever been told by a doctor that they had a hiatal hernia of the diaphragm, a chronic cough, or chronic bronchitis or emphysema. Participants were also asked about their frequency and quantity of beer, wine, and liquor consumption; alcohol use (number of drinks per day) was summarized as none, <1, 1–2, or >2. Women were asked whether their menstrual periods had stopped entirely. Weight (kg), standing height (cm), and sitting height (cm) were measured. Body mass index (weight (kg)/(height (m)2) was calculated, and participants were categorized as normal weight (<25), overweight (25–<30), or obese (
30). The presence of an umbilical hernia was noted upon physical examination. Demographic variables were age (25–39, 40–59, or 60–74 years), sex, race/ethnicity (White, Black, other), education (less than high school graduation, high school graduation or more), and urbanicity (urban or rural residence). Information on smoking (never, former, current) obtained in a subgroup was supplemented by responses to questions on lifetime smoking history posed to all participants in the 1982–1984 interview (12). A randomly chosen subgroup of 79 percent of participants were asked about their minimum and maximum adult weights. Weight loss from the maximum adult weight before baseline and weight gain from the minimum adult weight before baseline were calculated from reported weights and measured baseline weight.
NHANES I Epidemiologic Follow-up Study
The NHANES I Epidemiologic Follow-up Study was a longitudinal study of the 14,407 NHANES I participants aged 25–74 years who had been medically examined. It was conducted in four waves: 1982–1984, 1986, 1987, and 1992–1993 (11, 13–15). Ninety-six percent of the baseline cohort was recontacted. Participants were interviewed and hospital and nursing home records were collected at each wave. Records were obtained for all overnight medical facility stays occurring since the participant's NHANES I examination. Hospital discharge and nursing home admission diagnoses were recoded by trained medical coders using the International Classification of Diseases, Ninth Revision, Clinical Modification (16). We defined a case of inguinal hernia as any facility stay with an International Classification of Diseases, Ninth Revision, Clinical Modification, diagnosis that had a three-, four-, or five-digit code for which the first three digits were 550, inguinal hernia. Because outpatient hernia repairs became increasingly common over the 20 years of follow-up, participants were asked at the 1992 interview if they had ever been told by a doctor that they had a hernia or rupture of the groin (inguinal hernia), and if so, in what year they were first told of the diagnosis. Of 620 inguinal hernia cases, 373 were first-facility-stay diagnoses (99 percent were hospitalizations and 1 percent were nursing home admissions) and 247 were physician diagnoses reported at the 1992 interview among persons without a preceding facility-stay diagnosis. The date of diagnosis was considered to be the admission date of the first facility stay with an inguinal hernia diagnosis or the reported date of first physician diagnosis among persons without a documented facility-stay diagnosis.
Excluded from the current analysis were 546 survey participants who could not be traced, 288 who in 1992 reported a doctor-diagnosed inguinal hernia first diagnosed in a year prior to the year of their NHANES I examination, and 121 who in 1992 reported a doctor-diagnosed inguinal hernia with the year of first diagnosis unknown. Remaining for analysis were 13,452 persons (5,316 men and 8,136 women) with a median follow-up time of 18.2 years (range, 0.02–22.1 years).
Statistical analysis
For each level of potential risk factors, we calculated the cumulative percentage of participants with inguinal hernia during the 20 years of follow-up. We estimated curves for percentage with inguinal hernia (reciprocal of the survival curve) by categories of possible risk factors using Kaplan-Meier analysis. We then calculated hazard ratio estimates using Cox proportional hazards regression models in SAS (PROC PHREG and SAS OnlineDoc, version 8; SAS Institute, Inc., Cary, North Carolina) to take into consideration varying lengths of follow-up. Time at risk was calculated from the date of the NHANES I examination to the date of inguinal hernia diagnosis for cases or the date of last contact or death for noncases. All factors met the proportional hazards assumption of a relatively constant risk ratio through examination of -log (-log) plots of survival by duration of follow-up (17). For each possible risk factor, we conducted analysis adjusting for age (in 10-year groups) as an ordinal variable. The relation of incident inguinal hernia with potential risk factors was examined further in multivariate proportional hazards analysis while controlling for effects of multiple factors. Factors that were related to inguinal hernia in age-adjusted analysis (p < 0.10) were included in multivariate models. Multivariate analyses excluded persons with missing values for any risk factor included in the model. The trend in the relative risk of inguinal hernia across categories of risk factors was computed by including each factor in analyses as an ordinal variable with multiple levels. Because cases were based on physician diagnoses, either identified from hospital records or reported at the 1992 follow-up, and persons who are hospitalized or visit a physician are a selected group, we repeated the analyses in the population subgroup with one or more facility stays.
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RESULTS |
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The cumulative incidence of hospitalization with inguinal hernia was 6.3 percent at 20 years and was much higher among men (13.9 percent; 500 cases) than among women (2.1 percent; 120 cases) (figure 1). Adjusted for age, the inguinal hernia hazard ratio for men relative to women was 7.5 (95 percent confidence interval (CI): 6.2, 9.2). Consequently, more detailed analyses were conducted in men. The 20-year cumulative incidence of inguinal hernia among men increased with baseline age: 7.3 percent at age 24–39 years, 14.8 percent at age 40–59 years, and 22.8 percent at age 60–74 years (table 1, figure 2). White men had almost twice the 20-year cumulative incidence (15.1 percent) of Black men (8.4 percent). The relation of inguinal hernia with possible risk factors was examined in age-adjusted analysis. A lower incidence of inguinal hernia was associated with higher levels of some weight-related factors, including body mass index and maximum lifetime weight (table 1, figure 3). Men reporting a doctor-diagnosed hiatal hernia had a higher incidence of inguinal hernia. Current smokers had a borderline lower risk of inguinal hernia. Factors that were unrelated to inguinal hernia included nonrecreational and recreational physical activity, constipation or bowel movement frequency, chronic cough, chronic obstructive pulmonary disease, alcohol intake, minimum adult weight, weight loss or weight gain, height, and education.
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In multivariate analysis among men, greater age and a doctor-diagnosed hiatal hernia remained associated with a higher incidence of inguinal hernia, while Black race and overweight and obesity remained associated with a lower incidence (table 2). Middle-aged men had over twice the incidence of younger men, and the risk increased to almost three times among older men. The presence of a hiatal hernia almost doubled the risk. Black men had slightly more than half the incidence of White men. Obese men had half the risk of normal-weight men, while incidence was intermediate among the overweight. Recoding body mass index as a continuous variable resulted in a 4.7 percent lower risk of inguinal hernia for each unit increase in body mass index (p < 0.001). Other weight-related factors were not associated with inguinal hernia independently of body mass index.
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When analysis was limited to men with one or more medical facility stays (n = 3,452), there were 337 inguinal hernia facility-stay diagnoses, 67 percent of the number without this restriction. Results were similar in direction to those for the entire population, though they no longer reached statistical significance for Black race or doctor-diagnosed hiatal hernia. In multivariate-adjusted analysis, a higher incidence of inguinal hernia was found with middle age (hazard ratio (HR) = 1.7, 95 percent CI: 1.2, 2.3) and older age (HR = 2.3, 95 percent CI: 1.6, 3.2), while a lower incidence was found with overweight (HR = 0.76, 95 percent CI: 0.61, 0.95) and obesity (HR = 0.50, 95 percent CI: 0.34, 0.75). Associations with Black race (HR = 0.74, 95 percent CI: 0.52, 1.1) and hiatal hernia (HR = 1.5, 95 percent CI: 0.92, 2.5) were of borderline statistical significance.
Among women, older age was associated with a greater incidence of inguinal hernia. Other factors associated with a higher inguinal hernia incidence in age-adjusted analyses were rural residence, greater height, chronic cough, umbilical hernia, greater sitting height, and postmenopausal status. Sitting height and postmenopausal status were highly correlated with standing height and age, respectively, and therefore were not included in multivariate-adjusted analyses. Middle and older age, rural residence, height in the upper two thirds, chronic cough, and umbilical hernia remained independently associated with higher incidence of inguinal hernia in multivariate-adjusted analysis (table 3). Among women, multivariate-adjusted hazard ratios for Black race (HR = 0.68, 95 percent CI: 0.37, 1.3) and hiatal hernia (HR = 1.7, 95 percent CI: 0.74, 4.0) were similar to those among men but did not reach statistical significance. Overweight (HR = 0.99, 95 percent CI: 0.64, 1.5) and obesity (HR = 1.1, 95 percent CI: 0.71, 1.8) were unrelated to inguinal hernia among women.
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DISCUSSION |
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TOPABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONReferences |
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Possibly the clearest message of this study is how commonly inguinal hernia occurs. Many health-care providers may consider inguinal hernia to be largely limited to male infants with an anatomical defect in the inguinal canal (18). In contrast, we have documented that inguinal hernia occurs frequently among adults, such that well over one quarter of adult men in the United States would be expected to have a medically recognized inguinal hernia. In fact, the incidence of inguinal hernia increased noticeably with age among men.
An unexpected finding was the lower incidence of inguinal hernia among overweight and obese men as compared with normal-weight men. The risk among overweight men was 80 percent of that of normal-weight men, and the risk among obese men was only 50 percent of that of normal-weight men. It is possible that our findings resulted from ascertainment bias due to greater difficulty in diagnosing hernia among heavier persons. On the other hand, overweight and obese persons have more comorbidity requiring medical care and have a greater opportunity for a hernia diagnosis, which actually could have led to underestimation of the strength of a protective effect in our analysis. Among men with at least one facility stay, the lower risks of hernia among the overweight and obese were unchanged, while the strength of association of age, race, and hiatal hernia were diminished. Thus, receipt of medical care does not explain the lower risk of inguinal hernia among the overweight and obese.
A lower risk of inguinal hernia with overweight and obesity was also suggested in a community survey of men in Israel (3) and in a hospital-based case-control study of women in the Netherlands (6). A plausible explanation for a protective effect of greater adiposity exists in that among heavier men, abdominal wall musculature may be strengthened by carrying excess fat, providing a stronger barrier against herniation. If this is true, one might expect a central fat distribution, in particular, to be protective. However, we did not have information available on waist circumference or other measures of abdominal fat. More research is needed to determine whether the association of inguinal hernia with overweight and obesity is real. The effect of body fat distribution needs to be investigated as well.
The incidence of inguinal hernia was much higher in men than in women, as has been previously shown (2). Factors that were independently associated with a higher incidence of inguinal hernia among women were middle or older age, rural residence, height in the upper two thirds, chronic cough, and umbilical hernia.
Among men, we found an incidence of inguinal hernia among Blacks that was less than 60 percent of that of Whites. This lower rate of hernia among Black men could have resulted from a lower rate of utilization of medical care, with less opportunity for a hernia diagnosis. Among men with at least one facility stay, Blacks had a lower risk of hernia, although this result no longer reached statistical significance. Racial differences in body mass index could also have contributed, but the lower incidence in Blacks remained in multivariate-adjusted analysis.
The final factor that we found to be associated with a greater incidence of inguinal hernia was doctor-diagnosed hiatal hernia, which almost doubled the risk. Some men who reported a doctor-diagnosed hiatal hernia at baseline may have confused it with a history of inguinal hernia. However, an association between the two types of hernias was also seen in an Italian case-control study of endoscopy-diagnosed hiatal hernia (7). In that report, the risk of inguinal hernia upon physical examination was increased 2.5-fold among persons with hiatal hernia, though the older age of the hiatal hernia patients may have confounded the relation. An association between these two forms of hernia could be due to a common mechanism of increased intraabdominal pressure.
Increased intraabdominal pressure has long been suspected in the pathogenesis of inguinal hernia, though with little quantitative evidence. We investigated but did not find an association with additional factors that might exert an effect through such a mechanism, including physical activity, constipation, chronic cough, and chronic obstructive pulmonary disease. Our physical activity measure was limited to two interview questions, each with three possible subjective responses. An increased risk of inguinal hernia with greater physical exertion was found in two Spanish hospital-based case-control studies investigating occupational activity (4) or both work and recreational activity (5), while greater current sports activity was found to decrease the risk among Dutch women (6). There was no relation with work-related physical activity among Israeli men (2). Other factors that might increase intraabdominal pressure were not associated with inguinal hernia in previous studies, with the exception of an increased risk with obstipation in the Dutch study (3, 5, 6).
Structural weakness of the supporting tissue is another potential mechanism in the pathogenesis of inguinal hernia. A defect in collagen synthesis by fibroblasts has been suggested as a cause of inguinal hernia (19, 20). Smoking, which may adversely affect connective tissue metabolism, has been proposed as a risk factor for inguinal hernia (21) and was associated with hernia recurrence among smokers in one study (8). We did not find an increased incidence of inguinal hernia among current or former smokers. However, smoking may have a greater adverse effect on connective tissue healing than on intact connective tissue. Smoking was also unrelated to a first hernia diagnosis in previous reports (5, 6). Likewise, no relation of inguinal hernia with alcohol intake was seen in our study or in a previous one (5).
Our study had limitations. Because follow-up occurred between 10 and 20 years after the baseline examination, it is possible that some participants may have developed an inguinal hernia and died of complications, or may have been lost to follow-up for other reasons related to the hernia, in the intervening period. However, the follow-up rate was high (96 percent of persons in the baseline cohort were recontacted) and proxies were interviewed in the case of deceased participants, so this should have minimally biased the results. Secondly, because the case definition was based on hospital diagnoses and self-reported physician diagnoses, case ascertainment may have been incomplete. Confirmation of diagnoses by physical examination and chart review was not possible. Finally, although rates of participation and follow-up were high, participation and follow-up were incomplete, which decreases generalizability. Despite these limitations, our study contributes prospective data from a US population to the limited body of literature on risk factors for inguinal hernia.
In conclusion, in the US population, inguinal hernia is a common condition among men that increases substantially with aging. The lower risk among overweight and obese men was an unexpected finding that bears further study.
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ACKNOWLEDGMENTS |
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This work was supported by a contract (N01-DK-1-2478) with the National Institute of Diabetes and Digestive and Kidney Diseases.
The authors thank Danita Byrd-Holt for computer programming assistance.
Conflict of interest: none declared.
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References |
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TOPABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONReferences |
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- Everhart JE. Abdominal wall hernia. In: Digestive diseases in the United States: epidemiology and impact—Everhart JE, ed. (1994) Bethesda, MD: National Institute of Diabetes and Digestive and Kidney Diseases. 471–507.
- Kochanek KD, Murphy SL, Anderson RN, et al. Deaths: final data for 2002. (2004) Hyattsville, MD: National Center for Health Statistics. (National vital statistics reports, vol 53, no. 5).
- Abramson JH, Gofin J, Hopp C, et al. The epidemiology of inguinal hernia. A survey in western Jerusalem. J Epidemiol Community Health (1978) 32:59–67.[Abstract]
- Flich J, Alfonso JL, Delgado F, et al. Inguinal hernia and certain risk factors. Eur J Epidemiol (1992) 8:277–82.[ISI][Medline]
- Carbonell JF, Sanchez JL, Peris RT, et al. Risk factors associated with inguinal hernias: a case control study. Eur J Surg (1993) 159:481–6.[ISI][Medline]
- Liem MS, van der Graaf Y, Zwart RC, et al. Risk factors for inguinal hernia in women: a case-control study. The Coala Trial Group. Am J Epidemiol (1997) 146:721–6.
[Abstract/Free Full Text] - De Luca L, Di Giorgio P, Signoriello G, et al. Relationship between hiatal hernia and inguinal hernia. Dig Dis Sci (2004) 49:243–7.[CrossRef][ISI][Medline]
- Sorensen LT, Friis E, Jorgensen T, et al. Smoking is a risk factor for recurrence of groin hernia. World J Surg (2002) 26:397–400.[CrossRef][ISI][Medline]
- Miller HW. Plan and operation of the Health and Nutrition Examination Survey, United States 1971 –1973. Part A—development, plan, and operation. (1973) Hyattsville, MD: National Center for Health Statistics. (Vital and health statistics, series 1, no. 10a) (DHEW publication no. (PHS) 76-1310).
- Engel A, Murphy RS, Maurer K, et al. Plan and operation of the NHANES I Augmentation Survey of adults 25–74 years, United States 1974 –1975. (1978) Hyattsville, MD: National Center for Health Statistics. (Vital and health statistics, series 1, no. 14) (DHEW publication no. (PHS) 78-1314).
- Cohen BB, Barbano HE, Cox CS, et al. Plan and operation of the NHANES I Epidemiologic Followup Study, 1982 –84. (1987) Hyattsville, MD: National Center for Health Statistics. (Vital and health statistics, series 1, no. 22) (DHEW publication no. (PHS) 87-1324).
- McLaughlin JK, Dietz MS, Mehl ES, et al. Reliability of surrogate information on cigarette smoking by type of informant. Am J Epidemiol (1987) 126:144–6.
[Free Full Text] - Finucane FF, Freid VM, Madans JH, et al. Plan and operation of the NHANES I Epidemiologic Followup Study, 1986. (1987) Hyattsville, MD: National Center for Health Statistics. (Vital and health statistics, series 1, no. 25) (DHEW publication no. (PHS) 90-1307).
- Cox CS, Rothwell ST, Madans JH, et al. Plan and operation of the NHANES I Epidemiologic Followup Study, 1987. (1992) Hyattsville, MD: National Center for Health Statistics. (Vital and health statistics, series 1, no. 27) (DHEW publication no. (PHS) 92-1303).
- Cox CS, Mussolino ME, Rothwell ST, et al. Plan and operation of the NHANES I Epidemiologic Followup Study, 1992. (1997) Hyattsville, MD: National Center for Health Statistics. (Vital and health statistics, series 1, no. 35) (DHEW publication no. (PHS) 98-1311).
- US Department of Health and Human Services. International classification of diseases, ninth revision, clinical modification. (1991) Vol 1, 4th ed. Tabular list of diseases. Washington, DC: US GPO, 1991. (DHHS publication no. (PHS) 91-1260).
- Ingram DD, Makuc DM. Statistical issues in analyzing the NHANES I Epidemiologic Followup Study. (1994) Hyattsville, MD: National Center for Health Statistics. (Vital and health statistics, series 2, no. 121) (DHHS publication no. (PHS) 94-1395).
- Graf JL, Caty MG, Martin DJ, et al. Pediatric hernias. Semin Ultrasound CT MR (2002) 23:197–200.[CrossRef][ISI][Medline]
- Wagh PV, Read RC. Defective collagen synthesis in inguinal herniation. Am J Surg (1972) 124:819–22.[CrossRef][ISI][Medline]
- Ajabnoor MA, Mokhtar AM, Rafee AA, et al. Defective collagen metabolism in Saudi patients with hernia. Ann Clin Biochem (1992) 29:430–6.[ISI][Medline]
- Cannon DJ, Read RC. Metastatic emphysema: a mechanism for acquiring inguinal herniation. Ann Surg (1981) 194:270–8.[ISI][Medline]
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