Prevalence of overweight, obesity, and associated diseases among outpatients in a public hospital. (Original Article).

Background: The prevalence of obesity is increasing and may be particularly high among indigent public hospital patients. The purpose of this study was to determine the prevalence of obesity and its associated chronic medical conditions among outpatients at Louisiana State University Health Sciences Center-Shreveport, an urban tertiary health center that serves a mostly black, indigent population.

Methods: A cross-sectional survey was conducted on 1,507 primary care patients. Age, sex, weight, height, and diagnoses were recorded, and body mass index (BML) was calculated.

Results: Eighty-one percent of patients were overweight or obese and 75% had one or more obesity-associated conditions. Higher BMI was significantly associated with increased prevalence of obesity-related diseases (P < 0.001) even when adjusted for age and sex.

Conclusion: Overweight and obesity rates at this public hospital are alarming and may indicate a problem in public hospitals across the United States. The process and structure of care for overweight and obese patients need to be evaluated, and training for residents needs to address this problem.

The prevalence of overweight and obesity has increased I dramatically in the United States over the past two decades. Currently, more than 56% of American adults are overweight (body mass index [BMI], [greater than or equal to]25 kg/[m.sup.2] and 20% are obese (BMI, 30 kg/[m.sup.2]), according to a telephone survey in which respondents' self-reported weight and height were recorded. (1) The prevalence of overweight (64.5%) and obesity (30.5%) is higher when weight and height are measured. (2) The national self-report data indicate that obesity rates are higher among blacks (29%) and in southern states (23%) than in the U.S. general population. Louisiana, along with Mississippi and Alabama, ranks highest among the states. (1) Obesity is associated with significant adverse health consequences such as the development of diabetes mellitus type 2 (DM2), hypertension (HTN), dyslipidemia (DLP), coronary artery disease (CAD), cerebrovascular accident (CVA), osteoarthritis (OA), and obstructive sleep apnea (OSA). (3,4) Furthermore, the risk of death from all causes increases in the overweight or obese. (5) Approximately 300,000 adults die yearly in the U.S. as a consequence of obesity. (6)

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Obesity and its associated diseases not only have an adverse effect on health but also represent a tremendous economic burden. (1,3,7) The direct costs of obesity were estimated to be 5.7% of the U.S. national health expenditure in 1995. (8) The economic burden of obesity and its associated diseases may increase if the current epidemic of overweight and obesity is not controlled. (9)

Those at highest risk for obesity in the United States are minorities with low socioeconomic status, (9) many of whom are also without health insurance and thus medically indigent. (10) Public hospitals in the U.S. are largely responsible for the health care of these patients and therefore must bear the economic burden of obesity. It is important to determine the prevalence of overweight and obesity in a medically indigent population as a first step in providing a higher quality of care in this vulnerable population. Thus, the purpose of this study was to determine the prevalence of overweight and obesity and the diseases associated with obesity in primary care clinic patients at a university-based, public hospital.

Methods

In 2001, a cross-sectional survey was conducted over a 2-month period on 1,507 consecutive patients followed by internal medicine residents in two primary care clinics at Louisiana State University Health Sciences Center-Shreveport (LSUHSC). These two clinics serve an indigent population of approximately 30,000 outpatients annually, with fewer than 1% commercially insured and more than 75% black." During each office visit, patient age, sex, weight, height, and medical diagnoses as charted on a master problem list by residents were obtained from the latest clinic record. Weight and height were routinely measured for all patients with their shoes off by the nursing staff in both clinics and recorded on the chart. The scale used was Detecto Model 8430 (Detecto/Cardinal Scale Manufacturing Co., Inc., Webb City, MO), which is accurate to a weight of 400 lb. BMI was calculated as body weight in kilograms divided by height in meters squared. Blood pressure cuffs in larger sizes were used to accommodate obese patien ts. There were no missing data regarding patient weight, height, age, and sex. Clinical diagnoses were made on the basis of only the chart entries of the latest clinic visit. The LSUHSC Institutional Review Board approved the study design.

Descriptive statistics were computed with the use of Microsoft Excel (Microsoft Corp., Redmond, WA). Logistic regression analysis was performed with SAS software version 8.2 (SAS Institute, Inc., Cary, NC). Categorical data were compared with the use of the test, and Student's t test was used for continuous variables.

Results

Sixty-eight percent of the patients were female. The mean patient age was 54 years (range, 17-91 years). The median BMI was 32 (range, 15-74). Eighty-one percent of the patients were overweight or obese as defined by BMI ([greater than or equal to]25), and 14% were extremely obese (Class 3 obesity, BMI [greater than or equal to]40) (Fig. 1). Only 1% of patients were underweight (BMI, < 18.5). Although significantly more males (36.8%) than females (25%) were overweight (BMI 25-29.9) ([chi square] = 21.9, P < 0.0001), significantly more females (58%) than males (40%) were obese (BMI [greater than or equal to]30) ([chi square] = 22.7, P < 0.0001). The prevalence of obesity by age is shown in Table 1. Obesity as a clinical diagnosis was documented in the latest clinic note in only 2.3% of patients with a BMI of 30 or above.

Seventy-five percent of all patients reviewed had one or more obesity-associated diseases, including DM2, HTN, DLP, CAD, OA, CVA, and OSA. Of the 81% overweight or obese patients surveyed, 80% had one or more obesity-associated diseases. In contrast, of the 18% of patients with normal weight, 56% had obesity-associated diseases (P < 0.0001). The prevalence of HTN (P < 0.0001), DM2 (P < 0.0001), DLP (P < 0.02), and OA (P < 0.03) were significantly higher in overweight patients. There was considerable overlap of the obesity-related diseases within the study population. For example, 85% of patients with DM2, 86% with DLP, and 84% with CAD were also hypertensive. Among hypertensive patients, 49% had one or more of the following diseases: DM2, DLP, and CAD.

Patients with obesity-associated disorders were older than those who were disease-free ([chi square] = 19.8, P < 0.0001). Women were more likely than men to have HTN ([chi square] 4.73, P < 0.03), whereas men were more likely than women to have CAD ([chi square] = 15.09, P < 0.0001) and CVA ([chi square] = 9.35, P < 0.003). Higher BMI was significantly associated with HTN and DM2 and the total number of coexisting obesity-related diseases, even when adjusted for age and sex (Table 2).

Discussion

Public hospitals in the United States are increasingly responsible for the health care of indigent minority patients at high risk for obesity. The prevalence of obesity among general medical patients in this public hospital is much higher than that reported as the national estimates for blacks (52 versus 29%) and the general southern population (52 versus 23%). (1) Furthermore, the prevalence of Class 3 obesity (BMI [greater than or equal to] 40) is much higher among our patients than in the general population (14 versus 2.2%). Consistent with national data, (2, 12) the prevalence of obesity was significantly higher in women than in men. These study findings are particularly noteworthy, because the BMI data were calculated on the basis of patients' weight and height as measured by health care professionals rather than by patient self-report.

In parallel with the high prevalence of overweight and obesity, the prevalence of obesity-associated diseases was also remarkably high. Patients with BMI [greater than or equal to]25 had significantly more obesity-related diseases. In particular, DM2 was much more prevalent among our patients than has been reported previously in the general population (28 versus 7.3%). (1) Moreover, a large proportion of our patients had multiple obesity-related medical conditions, including HTN, DM2, DLP, and obesity suggestive of the metabolic syndrome, which is strongly associated with the development of CAD. (13-20)

In general, body weight reaches its maximum in the mid-50s for both sexes. (21) In our patient population, however, the highest mean BMI (32.5) was found in the 40- to 49-year-old age group. The results of this investigation also indicate that patients without obesity-associated diseases in all BMI categories were younger than those with obesity-related diseases. Because both older age and higher BMI are associated with an increased prevalence of obesity-associated diseases, and because of the higher BMI at a younger age in this patient population, interventions directed at younger patients may delay or attenuate obesity-related morbidity and mortality.

Although age and sex contribute to the occurrence of certain obesity-related medical conditions, BMI remains an independent risk factor for patients with these conditions. This suggests that weight control is as important for patient health care as the treatment of obesity-related diseases.

Despite increasing media attention and the fact that obesity is among the 10 most common diagnoses in both university and community ambulatory medicine practices, (22) the results of this study suggest that obesity may be underdocumented in public health settings. The clinical diagnosis of obesity was documented on a master problem list in only 2.3% of patients with a BMI of 30 or above. This rate may have been underestimated, however, because it was determined on the basis of only one clinic record. Also, it is possible that residents pay more attention to the complications of obesity rather than to obesity itself.

Previous studies have determined the effects of documenting obesity. McArtor et al (23) found that when obesity was documented on the problem list, management actions were taken for 92.9% of patients. The literature also indicates, however, that health care providers are often pessimistic about patient compliance and the success of weight loss therapy. Resident training and faculty development need to help physicians bridge the gap between the guidelines for standard care and documentation of weight management and actual practice. In addition, training needs to address providers' beliefs and attitudes regarding obesity and weight loss. (24,25)

The data in this study should be generalized with caution. Patient charts in only one public hospital in a southern city were reviewed. The data collected in this cross-sectional study do not directly address the underlying causes of the high prevalence of obesity and related diseases in this population. Furthermore, the documentation of obesity and other diseases was based on a master problem list generated from the latest clinic record only and did not take into account the possibility of previous documentation of obesity by the same or a different resident. Thus, the documentation of medical problems including obesity may have been underestimated. Patient race and insurance status were not obtained, because they are not indicated on the clinic record to maintain patient confidentiality. Therefore, the ethnic makeup and insurance status are reported on the basis of a previous survey in the same population. However, a recent computer survey of the same primary care clinics suggests that the patient demograph ics are essentially unchanged (unpublished data).

Many population-based surveys of obesity and related diseases are based on patient self-report of weight, height, and diagnoses. In contrast, an important strength of the present investigation is that BMI was calculated on the basis of weight and height as measured by health care professionals, and the clinical diagnoses are reported on the basis of data abstracted from the medical record. In addition, the large sample size adds power to the study.

Obesity and its comorbidities continue to pose a significant problem in the care of the underserved. In our hospital, more than 50% of general medical clinic patients were found to be obese, yet obesity was documented in only 2.3% of those patients. These findings have tremendous implications for this hospital and perhaps for other public hospitals in the United States. Currently, there is no formal weight management program for patients and no formal training for residents. Furthermore, there are no special waiting-room chairs or examination gowns to meet the needs of the 14% of patients who are extremely obese, although there are appropriately sized blood pressure cuffs. This public hospital's passive approach to this problem is a major concern, given the growing epidemic of obesity. Assessment of hospital infrastructure, patient education, and physician training is needed to provide higher-quality care for overweight and obese patients.

Table 1

Study patient body mass index distribution by age (a)

Age range     No. of        Mean BMI     BMI1  BMI2  BMI3  BMI4  BMI5
(yr)       patients (%)  (Kg/[m.sup.2])   (%)   (%)   (%)   (%)   (%)

17-29       104 (6.9%)        28.9         36    29    12     8    16
30-39       171 (11.3%)       31.1         21    29    19    17    14
40-49       323 (21.4%)       32.5         16    29    21    15    18
50-59       430 (28.5%)       31.9         15    27    26    16    16
60-69       317 (21.0%)       30.6         19    29    28    15     9
70+         162 (10.7%)       29.0         25    36    25     5     9
Total      1507 (100%)        31.1         19    29    24    14    14

(a)BMI, body mass index: BMI1 18.5-24.9 kg/[m.sup.2] (normal weight):
BMI2, 25-29.9 kg/[m.sup.2] (overweight); BMI3, 30-34.9 kg/[m.sup.2]
(class 1 obesity); BMI4, 35-39.9 kg/[m.sup.2] (class 2 obesity); BMI5,
[greater than or equal to]40 kg/[m.sup.2] (class 3 obesity).

Table 2

Age-and sex-adjusted OR between BMI and diseases

                                         BMI category (a)
Diagnosis                       BMI1      BMI2        BMI3

Type 2 diabetes mellitus
 OR                             1.00      2.16        3.88
 95% CI                                   1.42-3.28   2.56-5.88
 P value                                  <0.001      <0.001
Hypertension
 OR                             1.00      2.30        2.84
 95% CI                                   1.61-3.27   1.95-4.13
 P value                                  <0.001      <0.001
1 Obesity-related diagnosis(b)
 OR                             1.00      2.35        2.14
 95% CI                                   1.55-3.55   1.35-3.39
 P value                                  <0.001      <0.001
2 Obesity-related diagnoses
 OR                             1.00      4.48        6.36
 95% CI                                   2.62-7.67   3.59-11.27
 P value                                  <0.001      <0.001
3 + Obesity-related diagnoses
 OR                             1.00      5.27        14.41
 95% CI                                   2.34-11.86  6.49-32.01
 P value                                  <0.001      <0.001

                                    BMI category (a)
Diagnosis                       BMI4        BMI5

Type 2 diabetes mellitus
 OR                             3.99        4.68
 95% CI                         2.53-6.30   2.97-7.39
 P value                        <0.001      <0.001
Hypertension
 OR                             5.66        5.70
 95% CI                         3.58-8.97   3.62-9.00
 P value                        <0.001      <0.001
1 Obesity-related diagnosis(b)
 OR                             5.04        4.19
 95% CI                         2.90-8.75   2.41-7.28
 P value                        <0.001      <0.001
2 Obesity-related diagnoses
 OR                             11.91       14.41
 95% CI                         5.99-23.69  7.30-28.43
 P value                        <0.001      <0.001
3 + Obesity-related diagnoses
 OR                             14.95       16.32
 95% CI                         5.89-37.95  6.38-41.74
 P value                        <0.001      <0.001

(a)BMI Categories: BMI1, 18.5-24.9; BMI2, 25-29.9; BMI3, 30-34.9; BMI4,
35-39.9; BMI5, [greater than or equal to]40. OR, odds ratio; CI,
confidence interval.

(b)Diagnosis of one, two, or three or more out of the seven
obesity-related diseases including hypertension, diabetes mellitus
type 2, dyslipidemia, coronary artery disease, osteoarthritis,
cerebral vascular accident, and obstructive sleep apnea.

Fig. 1

BMI distribution of study participants, 1, underweight (BMI, <18.5); 2,
normal weight (BMI, 18.5-24.9); 3, overweight (BMI, 25-29.9); 4, obese I
(BMI, 30-34.9); 5, obese II (BMI, 35-39.9); 6, obese III (BMI, [greater
than or equal to] 40).


1   1%
2  18%
3  29%
4  24%
5  14%
6  14%

Note: Table made from pie chart

Accepted November 14, 2002.

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RELATED ARTICLE: Key Points

* The prevalence of overweight and obesity among indigent patients is high.

* The prevalence of obesity-related diseases among indigent patients is high.

* Indigent patients who are obese often have multiple, overlapping chronic illnesses.

* Obesity is underdocumented as a clinical diagnosis.

From the Department of Medicine, Louisiana State University Health Sciences Center, Shreveport, LA; and the Department of Epidemiology and Public Health, Yale University School of Medicine, New Haven, CT.

Reprint requests to Jian Huang, MD, Section of General Internal Medicine, Department of Medicine, Louisiana State University Health Sciences Center at Shreveport, P.O. Box 33932, 1501 Kings Highway, Shreveport, LA 71130-3932. Email: [e-mail]

Copyright [c] 2003 by The Southern Medical Association