en million people in the United States complained of hemorrhoids, corresponding to a prevalence rate of 4.4% (95% confidence interval, 4.2%- 4.6%) (17-20). Of these, approximately one third presented to physicians for evaluation, and an average of 1.5 million prescriptions were written annually for hemorrhoidal preparations. Although hemorrhoids were common, they rarely led to significant morbidity. Hospitalization for hemorrhoids occurred in only 12.9 (12.4-13.4) per million population (Table 1).
The age distribution of hemorrhoids demonstrated a hyperbolic pattern with a peak between age 45 and 65 yr and a subsequent decline after age 65 yr (Figure 1). The presence of hemorrhoids in patients aged ~20 yr was unusual. This pattern was similar for all measures of occurrence, i.e., prevalence, physician visits, and hospital discharges. By contrast, constipation was common in children, declined in frequency in middle age, and increased exponentially after age 65 yr (Figure 1). The two age distributions were significantly different when tested by x2 (p < 0.001). Male and female subjects demonstrated similar hyperbolic age distributions. No significant difference was evident in the occurrence of hemorrhoids between the sexes. According to statistics from the NDTI and NHDS, hemorrhoids were slightly more common in male than female subjects. In the NHIS and the MSGP, hemorrhoids were more common in female than male subjects.
Comparison of age-specific prevalence rates of hemorrhoids between whites and blacks again demonstrated hyperbolic age distributions (Figure 21. The overall prevalence of hemorrhoids was 1.5 times greater in whites than in blacks (p < 0.01). This difference was observed in all age categories (Figure 2).
Distribution by Geographic Region Hemorrhoids were 1.3 times more common in rural than urban areas (p < 0.05), occurring in 51 (41-61) per thousand persons residing in rural areas and 39 (32-46) per thousand persons living in cities. Table 1 illustrates the regional distribution of hemorrhoids in the United States. These data bases yield contrasting information about the regional prevalence of hemorrhoids. Prevalence data from the NHIS showed a different pattern than physician visit data from the NDTI, which again demonstrated a different pattern than hospital discharge data from the NHDS.
Distribution by Socioeconomic Status Analysis of MSGP data demonstrated a significant difference in the occurrence of hemorrhoids related to socioeconomic status. Hemorrhoids were 1.8 times more common in the highest than in the lowest social class (p < 0.002). The prevalence of hemorrhoids was significantly correlated with increasing social class (r = 0.943, p -C 0.01) (Figure 3). In married women categorized by their husbands’ social classes, no correlation between the presence of hemorrhoids and social class was found (Figure 4). The association of hemorrhoids with socioeconomic status was less clear in data from the NHIS. No difference was observed between the different income groups. In contrast to hemorrhoids, the prevalence of constipation was inversely correlated with social class (r = -0.943, p < 0.011, showing a marked decline associated with increasing socioeconomic status. This pattern was seen both in the United States and in England and Wales (Figure 3). Men and women categorized by their husbands’ social classes showed parallel declines in constipation with increasing socioeconomic status.
Discussion
The demographic characteristics of hemorrhoids can be summarized as follows. Ten million people in the United States complained of hemorrhoids, corresponding to an overall prevalence rate of 4.4%. Hospitalizations resulting from hemorrhoids were uncommon. The age distribution of hemorrhoids demonstrated a hyperbolic pattern with a peak prevalence in subjects aged 45-65 yr. The prevalence of hemorrhoids was not significantly affected by gender. No distinctive regional distribution of hemorrhoids was demonstrated. Whites were affected significantly more frequently than blacks, and the presence of hemorrhoids was associated with increasing social class in men but not women.
Population-based data sources provide the best information for evaluating the prevalence of chronic diseases in the general population. No previous epidemiologic studies have used such data. In the design of these population-based surveys, substantial effort was devoted to obtaining a representative sample of the entire U.S. population to eliminate biases that may have been introduced in smaller or regional surveys. The surveys analyzed in the present study were selected because they provided different measures of the occurrence of hemorrhoids and constipation. The strength of the NHIS rests in its heterogeneity covering all strata of the U.S. population. The NHIS is limited by a lack of validation of self-reported disease occurrence. The strength of hospital discharge data is reliability. Data are taken directly from the patients’ records, but information is obtained only from the face sheet of the discharge record, which may be incomplete. The strength of physician visit data bases such as the NDTI and MSGP lies in their ability to provide an accurate estimation of the prevalence of diseases such as hemorrhoids and constipation that do not necessarily require hospitalization. Physician visit data may be limited by incomplete physician response rates, which may skew data to the characteristics of the reporting physicians.
Because patients may mistake other anorectal conditions for hemorrhoids, statistics based on physician diagnoses, such as NDTI or MSGP, may provide more accurate measures of the true prevalence of hemorrhoids in the general population than the NHIS. This could represent one explanation for the 4-fold difference between the prevalence rates of hemorrhoids found by the NHIS and the NDTI. A likely and obvious explanation for this difference is that many more patients complained of hemorrhoids than consulted physicians for diagnosis and treatment. Interestingly, similar epidemiologic patterns were found in the NHIS and the other surveys. This similarity may give further credence to the observed epidemiologic behavior. On the other hand, confounding factors or systematic errors, which affect various data sources alike, could mask the true pattern and lead to skewed statistics. Symptoms alone do not allow the differentiation of hemorrhoids from other anorectal conditions. Constipation is a symptom complex arising from a heterogeneous group of disorders that frequently do not come to the attention of physicians. The term constipation may represent different problems to different patients because habits and concepts about defecation are influenced by social and dietary customs. Because neither constipation nor hemorrhoids is considered life threatening, the degree of complaints and health care-seeking behavior may be influenced by socioeconomic factors as well as the availability of self-treatment. Perceptions of constipation or hemorrhoids as something that is noteworthy or requires medical attention may also vary among different social or ethnic groups. Therefore, caution must be exercised when interpreting epidemiologic data regarding hemorrhoids and constipation.
Hemorrhoids are commonly considered a consequence of the aging process and increase in frequency with age (7). Results from the present study do not support this contention. Rather, it appears that the occurrence of hemorrhoids actually decreased with age. A hyperbolic age distribution of hemorrhoids was observed in all surveys. At present, the reason for these distributions is unclear. It could be related to decreased anal pressures associated with aging (26- 28). It may also be speculated that increased use of enemas or laxatives in the elderly for treatment of constipation could decrease the expression of hemorrhoids. In England and Wales, higher social class was correlated with increasing prevalence rates of hemorrhoids. No such pattern was found for varying income levels in the United States. Differences in the occurrence of hemorrhoids in England and the United States may be explained by differences in social classification. In the United States, family income is determined by other factors in addition to occupation. By contrast, social class is closely associated with occupation in England and Wales. Therefore, in England and Wales the risk associated with social class may primarily represent the occupations that underlie individuals’ assignment to social classes. This contention is supported by comparison of the occurrence of hemorrhoids in males with the occurrence in females categorized by their husbands’ social classes. If an environmental factor directly related to income level or social status influenced the development of hemorrhoids, married women and their husbands would be expected to demonstrate parallel epidemiologic distributions, unlike the male and female patterns shown in Figure 4. The possible influence of occupation on the development of hemorrhoids has previously been suggested by Prasad et al. (12). who noted that a majority of their patients with hemorrhoids had clerical, business, or sedentary occupations involving prolonged sitting while only 34% were engaged in manual labor or “ambulatory types of occupations” (12). As outlined above, however, the influence of other confounding factors in the socioeconomic distribution of hemorrhoids cannot be ruled out. The basis for the difference in the prevalence of hemorrhoids between urban and rural residents is unclear. Although statistically significant, this difference is small. Traditionally, urban dwellers have had higher income levels than rural dwellers. The apparent discrepancy between the urban and rural prevalences of hemorrhoids observed in the United States compared with the income level pattern observed in England and Wales may again suggest that socioeconomic factors are less important in the etiology of hemorrhoids in the United States than in England and Wales.
Constipation has long been implicated in the pathogenesis of hemorrhoids and is widely believed to be a major risk factor for hemorrhoids. In the early 1970s. Burkitt speculated that the occurrence of hemorrhoids was causally related to constipation, presumably because of a deficiency in dietary fiber (1,9,10). If constipation and hemorrhoids share a common etiologic risk factor, they should demonstrate similar epidemiologic patterns. From the results of the present study, the epidemiologic pattern of constipation appears to be divergent from that of hemorrhoids. The age distribution of constipation demonstrates an exponential increase with advancing age while a decrease in the occurrence of hemorrhoids after age 65 yr is observed. Constipation seems to be more common in blacks and in persons from families with low incomes or less formal education (291, while hemorrhoids seem to be more common in whites and in the higher social classes. Dissimilar epidemiologic behavior of hemorrhoids and constipation does not rule out a causal relationship, but the data presented here raise questions about the presumption of causality between constipation and hemorrhoids. Case-control studies may provide avenues of future investigation into the relationship between hemorrhoids and constipation.
References
(Source: gastrojournal.org [February 1990])
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