Recent guidelines for adolescent primary care call for the specification of clinical services by three adolescent age subgroups. Yet analyses of office visits have either merged adolescence into one stage or divided it at age 15 years.
Objective. To explore the utilization of physician offices in the United States by early (11–14 years), middle (15–17 years), and late (18–21 years) adolescents.
Design. Secondary analysis of the 1994 National Ambulatory Medical Care Survey, focusing on visits made by the three adolescent age groups.
Setting. Nationally representative sample of 2426 physicians in nonfederal, nonhospital offices.
Subjects. A total of 33 598 visits by patients of all ages, representing 681.5 million visits in 1994.
Main Outcome Measures. Number of visits, health insurance, providers seen, duration of visits, reasons for visits, resulting diagnoses, and counseling provided.
Results. Adolescents aged 11 to 21 years made 9.1% (61.8 million) of the total office visits and represented 15.4% of the total US population in 1994. This underrepresentation in visits held across all three adolescent age subgroups. Within the adolescent cohort, whites were overrepresented relative to their population proportion (78.5% of visits, 67.6% of population) and blacks and Hispanic adolescents were underrepresented (8.3% and 9.3% of visits, 15.5% and 13.1% of population). Middle adolescence signaled a life turning point from male to female predominance in office visits. Peak lifetime uninsurance rates occurred at middle adolescence for females (18.7%) and late adolescence for males (24.0%). Between childhood and early adolescence, public insurance decreased from 24.7% to 15.7% and uninsurance increased from 12.7% to 19.7%. Pediatricians accounted for the highest proportion of early adolescent visits (41.2%), family physicians for middle adolescent visits (35.3%), obstetrician-gynecologists for late adolescent female visits (37.3%), and family physicians for late adolescent male visits (34.8%). Mean visit duration during adolescence was 16 minutes, did not differ by age subgroup or sex, exceeded that of children (14.6 minutes), and was shorter than that of adults (19.3 minutes). Obstetrician-gynecologists spent more time with adolescents than did other physicians. Education or counseling was included in 50.4% of adolescent visits, ranging from 65.1% for obstetrician-gynecologists to 34.8% for internists. During early adolescence, the leading reasons for both male and female visits were respiratory (19.4%), dermatological (10.0%), and musculoskeletal (9.7%). A similar profile was found for middle and late adolescent males. For middle and late adolescent females, the leading reason for visits was special obstetrical-gynecological examination (12.8% and 21.1%), and the leading diagnosis resulting from visits was pregnancy (9.5% and 20.4%).
Conclusions. Adolescents underutilize physician offices and are more likely to be uninsured than any other age group. Visits are short, and counseling is not a uniform component of care. As adolescents mature, their providers, presenting problems, and resulting diagnoses change. The data from the National Ambulatory Medical Care Survey support a staged approach to adolescent preventive services, targeted to the needs of three age subgroups.
Adolescent health status in the United States has been the subject of many studies and public reports in recent years. The high rates of adolescent injury, homicide, suicide, substance use, sexually transmitted disease, and pregnancy have fostered a call for action on the part of social scientists, policy makers, and health care providers.1–8 Experts on adolescent health and development generally agree that the traditional biomedical approach to care will neither encourage adolescent utilization of services nor curtail the high cost of managing adolescent health crises. An approach centered on primary prevention rather than crisis intervention has become the organizing theme for the redesign of adolescent health services.9 ,10 Despite these efforts, however, recent studies suggest that adolescents continue to rely heavily on emergency services for their primary care needs.11–14 In 1994, adolescents aged 11 to 21 years overutilized emergency services relative to their population proportion, half their visits were nonurgent, and <5% resulted in hospitalization.11
In an effort to encourage the delivery and utilization of adolescent primary care, the federal government and health professional organizations have released clinical guidelines for these services. The Public Health Service and the American Medical Association developedGuidelines for Adolescent Preventive Services (GAPS). 9 The Maternal and Child Health Bureau developed Bright Futures: Guidelines for Health Supervision of Infants, Children, and Adolescents. 10 BothGAPS and Bright Futures call for the specification of adolescent clinical services by chronological stages defined as early (11–14 years), middle (15–17 years), and late (18–21 years) adolescence. It remains unclear, however, if the guidelines reflect the actual patterns of utilization or need of adolescents. Past studies of adolescent health services have not used the age stratification of the guidelines but instead have merged adolescence into one, or at best two, stages.6 ,7 12–14
The assessment of adolescent utilization is complicated by the assumption that adolescents tend to seek services other than those traditionally delivered through physician offices or hospital clinics. For example, in 1994, females aged 21 years and younger made an estimated 5.2 million visits to family planning clinics (Frost15; Frost JJ, the Allen Guttmacher Institute, New York, personal communication, 1998). An extrapolation of data from 1994/1995 reveals that adolescent males and females made during 1994 a maximum of 1.6 million visits to school-based health centers (Santelli et al,16 Klein and Cox,17McKinney and Peak,18 and Fothergill and Ballard19; Santelli J, Division of Adolescent and School Health, Centers for Disease Control and Prevention, Atlanta, GA, personal communication, 1998). Although these numbers probably are increasing, they remain substantially less than the estimated 61.8 million adolescent visits to physician offices,20 or 14.8 million visits to emergency departments,11 and 7.3 million visits to outpatient departments.21
In view of the importance of physician offices as sites of care, our goal was to explore the characteristics of these visits as adolescents mature during the second decade of life. Data from the 1994 National Ambulatory Medical Care Survey (NAMCS)20 were divided into three adolescent age groups, corresponding to the groups used byGAPS and Bright Futures.9 ,10 The specific objectives were to compare early, middle, and late adolescents for their numbers of visits relative to population proportions, physician specialties seen, health insurance status, visit reason and duration, resulting diagnoses, and primary care counseling.
NAMCS is a representative national probability sample survey of private, office-based physicians conducted annually by the National Center for Health Statistics.20 The data collected are weighted to produce national estimates that describe the utilization of ambulatory medical care services in the United States.
For 1994, a sample of 2426 nonfederal, office-based physicians was selected from master files maintained by the American Medical Association and the American Osteopathic Association. Seventy percent of the physicians contacted agreed to participate by documenting their patient visits during a randomly assigned 1-week period. The 33 598 documented visits represented an estimated 681.5 million visits made during 1994 to the offices of nonfederally employed physicians.
The patient visits were documented on standard forms that included variables such as patient age, sex, ethnicity, source of payment, reasons for the visit, diagnoses, diagnostic/screening services, counseling, and duration of visit. The reasons for the visits were recorded on presentation to the offices and coded according to the published reason for visit classification.22 Diagnoses were rendered at the completion of the visit and coded according to theInternational Classification of Diseases, 9th Revision, Clinical Modification. 23 A complete description of the NAMCS can be found in the 1994 NAMCS Data File Documentation.24Schappert20 has published a general summary of the 1994 NAMCS findings for visits made by patient of all ages. Census data were used to estimate the proportion of the US population in each age, sex, and race cohort. These data came from the 1994 Current Population Survey: Personal Data File. 25
Unlike simple random sampling, the four-stage probability design of the NAMCS does not result in an equal chance of selection for each patient visit in the target population. Consequently, population characteristics must be estimated through the use of sampling weights that correct for disproportionate representation.
The present analysis utilized sample weights and a simple approximation to explain the effects of the sample design on the variance of the calculated estimates. These adjusted variance estimates, which consider the clustering in the sample design, were used to calculate approximate standard errors. Although it is possible to compute more exact standard errors through resampling procedures,26 this approach requires variables that were not available on the public-use data tapes. Consequently, coefficients approximating the relative standard errors were used to adjust the variances of the patient-visit estimates.20 The SAS Statistical Software Package was used to derive the population estimates and approximate standard errors.27
The public-use data tapes of the NAMCS have strict release guidelines. Estimates with relative standard errors >30% (sample size < ∼63 000 visits) are not reportable. Approximate standard errors for all reported estimates are given in all tables. Statistical tests comparing the proportions of a given population visit characteristic were performed by calculating the standard error of the difference and using this value to obtain a t statistic. Because the standard errors are approximations, exact P values are not reported. Instead, t values < −2.3 or > +2.3 were considered statistically significant (approximate P values < .01).
An estimated 61.8 million office visits were made by adolescents aged 11 to 21 years during 1994 (Table 1). These visits represented 9.1% of the total office visits made by the US population. According to the 1994 census data, adolescents aged 11 to 21 years comprised 15.4% of the population. Adolescents therefore were underrepresented in their utilization of office visits. This underrepresentation held across the three adolescent age subgroups.
The distribution of all office visits by sex and race is shown in Table 2. During the course of adolescence, the proportion of visits made by males decreased. Overall, female adolescents accounted for more office visits than did male adolescents (57.1% vs 42.9%; P < .01). However, within each adolescent age subgroup, female visits significantly exceeded male visits only at age 18 to 21 years. Mid adolescence signaled a life turning point from male to female predominance in office visits. In early adolescence, visit rates were nearly identical for males and females at 147 and 146 per 100 population. By mid adolescence, the rates were 159 and 191 per 100 population. By late adolescence, male rates were less than half the female rates at 105 and 216 per 100 population.
White adolescents were overrepresented in office visits (see Table 2). They comprised 67.6% of the US adolescent population yet made 78.5% of the visits. Conversely, black and Hispanic adolescents comprised 15.5% and 13.1% of the population but made only 8.3% and 9.3% of the visits. Adolescents of all other races comprised 3.9% of the adolescent population and made 3.8% of the visits. With advancing age beyond adolescence, the disparity between the percentage of visits and percentage of population by race narrowed, although blacks continued to be underrepresented in visits throughout life.
Tables 3 and4 summarize the expected sources of payment for adolescent office visits in 1994. For these analyses, no evidence of insurance included visits in which patients self-paid, no charge was levied, and no payment was expected by any private or public insurance program. Visits in which patients had evidence of full or partial insurance coverage were categorized as private, public, or both private and public insurance. The combined category of both private and public insurance was negligible in all age groups except >65 years and is not included in the tables. It should be noted that expected source of payment is not necessarily equivalent to actual insurance. For example, no evidence of insurance may reflect the adolescent's decision to self-pay rather than the true lack of insurance.
Overall, 64.1% of adolescent visits were covered by private insurance, 15.7% by public insurance, and 19.7% by no insurance. Public insurance decreased between childhood and early adolescence among both males and females. The rate of public insurance for late adolescent females (23.6%) exceeded that of late adolescent males (12.6%,P < .01), mid adolescent females (14.5%,P < .01), and adult females aged 22 to 44 years. (12.6%, P < .01). The transition from childhood to adolescence was associated with an increase at P < .01 in the rate of uninsured visits (12.7% to 19.7%). Adolescents did not differ significantly, however, from adults aged 22 to 64 years in the rate of uninsured visits.
As shown in Table 4, the rate of uninsurance increased dramatically at age 11 years in all race/ethnic groups and persisted into adulthood. It was not until the population became eligible for Medicare by virtue of age that the uninsurance rate decreases. However, the types of coverage held by the insured population differed widely by race/ethnicity. At age 11 years, the proportional decline in public insurance was two times greater for white and Hispanic adolescents than for black adolescents. It decreased by 33.7% among whites, 31.2% among Hispanics, and 16.0% among blacks. Consequently, the greatest discrepancy by race was seen in the rates of public insurance rather than in the rates of no insurance.
As adolescents age, the specialty profile of the providers from whom they seek care changes (Table 5). Early adolescents were most likely to visit pediatricians. Middle adolescents and late adolescent males were most likely to visit general and/or family physicians. Late adolescent females were most likely to visit obstetrician-gynecologists. Between early and late adolescence, visits to pediatricians fell from 41.2% to 4.1% (P < .01). Overall, 68.1% of adolescent visits were to general/family physicians, pediatricians, internists, and obstetrician-gynecologists. Three other specialists (orthopedic surgeons, dermatologists, and psychiatrists) provided the care for 16.9% of all adolescent visits. The remaining 15.0% of adolescent visits was to physicians from all other specialties combined.
The mean visit duration for adolescents was 16.0 minutes (SE, 0.2 minutes). There were no significant differences in the mean duration for males (15.7 minutes; SE, 0.4 minutes) versus females (16.2 minutes; SE, 0.3 minutes) or early adolescents (15.6 minutes; SE, 0.4 minutes) versus late adolescents (16.5 minutes; SE, 0.5 minutes). For all adolescents aged 11 to 21 years, mean visit duration did not differ among obstetrician-gynecologists (16.6 minutes; SE, 0.6 minutes), internists (15.6 minutes; SE, 0.8 minutes), pediatricians (14.9 minutes; SE, 0.4 minutes), and general/family physicians (14.3 minutes; SE, 0.3 minutes). The mean visit duration for adolescents (16.0 minutes; SE, 0.2 minutes) was longer than that for children <11 years old (14.6 minutes; SE, 0.1 minutes; P < .01) but shorter than that for adults >21 years of age (19.3 minutes; SE, 0.1 minutes; P < .01).
As part of the report form used for data collection in the study, physicians were asked to report on counseling/educational interventions that occurred during their patient encounters. No counseling or education was noted in 49.6% of adolescent office visits. Counseling about exercise (7.9%) and growth and development (6.7%) was more common, at P < .01, than counseling about injury prevention (4.2%), weight reduction (2.3%), smoking cessation (1.6%), HIV (1.5%), or other sexually transmitted diseases (2.7%). No significant differences were found in the rates of counseling provided to males and females on any topic. However, differences atP < .01 were found between specialists in their rates of adolescent counseling. Obstetrician-gynecologists noted some counseling in 65.1% of encounters, pediatricians in 53.5%, general/family physicians in 44.7%, and internists in 34.8%. Obstetrician-gynecologists counseled about sexually transmitted diseases during 10.3% of visits, and pediatricians counseled about growth and development during 17.0% of visits. The rate of counseling on all other specific topics by the different providers was much lower, ranging from 0% to 7.6%.
The leading reason categories and principal reasons for adolescent office visits are shown in Tables 6 and7. There were no significant differences by sex in any categories except two. Visits for genitourinary complaints and special examination (most of which were pelvic and prenatal examinations) were more common among middle and late adolescent females than males (P < .01). Early and middle adolescent males and females and late adolescent males were most likely to present with respiratory (mostly sore throat and cough), dermatological (mostly acne and rash), and musculoskeletal (mostly knee pain) symptoms. Late adolescent females were most likely to present for special examinations, of which routine prenatal examinations were most prevalent. Routine prenatal examinations comprised 10.4% of female visits during middle adolescence and 17.8% of female visits during late adolescence.
The leading diagnostic categories and most common diagnoses resulting from office visits during adolescence are shown in Tables 8 and 9. Respiratory, V-codes, injury, and dermatology were the leading diagnostic categories. Normal pregnancy accounted for 3.9 million office visits, 9.5% of visits by females aged 15 to 17 years, and 20.4% of visits by females aged 18 to 21 years. Genitourinary diagnoses were also common among females during middle (8.4%) and late (10.4%) adolescence.
Recent guidelines for adolescent primary care offer a comprehensive and dynamic framework for the delivery of health services.9 ,10 The guidelines reflect the rapidly changing needs of patients during the second decade of life, specifying different strategies at ages 11 to 14, 15 to 17, and 18 to 21 years. The objective of our study was to apply this same age stratification to national data on health service utilization. Our analyses reveal important changes during the course of adolescence in the health services needed, sought, and provided. The findings support the design of service strategies that target age segments within adolescence rather than considering adolescence en bloc.
Early, middle, and late adolescents all underutilize physician offices relative to their population proportion. Early adolescents have the lowest rate of office visits of any age group across the life span. Although this underutilization may reflect better health status than other age groups, young adolescents initiate behaviors that pose escalating health risks well into adulthood. Between early and mid adolescence, the number of visits per 100 population increased 12%. Some of this increase may signal the increasing autonomy and access to primary care of the maturing adolescent. However, the reasons for the visits and the resulting diagnoses suggest that the increased visit rate reflects the adverse health sequelae of early adolescent risk behaviors rather than the improved utilization of primary, preventive services.
Despite increasing attention during the 1990s to adolescent health needs and barriers to care, our findings suggest little change in adolescent utilization of office-based services. NAMCS data collected during 1980 to 1981 revealed that adolescents aged 11 to 14 years and 15 to 20 years made 140 and 179 visits per 100 population, respectively.28 ,29 These rates are remarkably similar to the 147, 174, and 162 visits per 100 population made in 1994 by adolescents aged 11 to 14, 15 to 17, and 18 to 21 years. The decline in utilization between middle and late adolescence noted in our study has not been reported previously.
The decline in overall visits is entirely attributable to a dramatic decline in male visits, because female visits actually increased from early to mid to late adolescence. The increase in female visits is not explained by increased rates of preventive care visits but rather by increased visits for pregnancy and reproductive health problems. By late adolescence, the leading reason for female visits was prenatal or pelvic examination and the leading physician specialty was obstetrics-gynecology. We found no difference between males and females in early, mid, or late adolescence in their visit rates for general examination.
The declining utilization of nonemergency health services by males during adolescence is particularly disturbing given their simultaneously increasing rates of injury, homicide, suicide, sexually transmitted disease, and substance abuse.6 ,7 The older adolescent male is at high risk for morbidity and mortality, challenges the health care system with costly and often irreversible crises, yet provides limited opportunity for preventive counseling or early detection.
The problem of underutilization is even more compelling when considering the office visit rates of black and Hispanic compared with white adolescents. Between the 1980 to 1981 and the 1994 NAMC surveys, the rates for black adolescents fell from 111 to 86 visits per 100 population, whereas the rates for white adolescents increased from 177 to 187 visits per 100 population.28 ,29 In 1994, Hispanic adolescents underutilized physician offices relative to their population proportion, but other races (Asian/Pacific Islander and American Indian/Eskimo/Aleut) had visit rates consistent with their population proportion. The lower utilization of physician offices by black and Hispanic compared with white adolescents in 1994 is consistent with data from the 1988 National Health Interview Survey (NHIS).30 Lieu et al31 reported that black and Hispanic adolescents aged 10 to 17 years reported poorer health status than white adolescents yet made fewer physician visits for both preventive and sick care. Conversely, a recent analysis of emergency department utilization revealed that black adolescents were overrepresented relative to white adolescents.11 These studies suggest that minority youth may turn to emergency services for both their urgent and primary care needs.
Inadequate health insurance has long been recognized as a consistent and challenging obstacle to care for all adolescents in the United States and particularly for minority adolescents.4 ,12 31–38 Our study confirms many earlier reports demonstrating that uninsurance peaks during adolescence.32–35 Although rates vary somewhat across studies, public insurance typically declines between childhood and young adulthood without a compensatory increase in private insurance. It is noteworthy that we found this imbalance resulted in higher rates of no insurance for white (19.6%) than black (13.1%) adolescents. This finding differs from the 1988 rates of 11% for whites and 16% for blacks.31
There are several potential explanations for this discrepancy. First, our study included adolescents to age 21 years whereas the population of the National Health Interview Surveys included adolescents to age 18 years. The high rate of pregnancy among 18- to 21-year-old females resulted in an increase in public insurance between mid and late adolescence. Second, adolescents who make office visits probably are more likely to have some type of health insurance than the general population of adolescents. For example, Brindis et al36reported that adolescent visits to school-based clinics were highly correlated with private health insurance. Third, no insurance in our study may reflect an adolescent decision to self-pay and withhold insurance information (eg, for confidentiality) rather than a true lack of insurance.
Nonfinancial factors may be as important as health insurance in explaining the racial/ethnic differences in health care utilization. In an analysis of the 1987 National Medical Expenditure Survey, Bartman et al37 reported that inequities in symptom-based care for minority adolescents aged 11 to 17 years were related more to lack of a usual source of care than to health insurance or socioeconomic status. In the data from the 1988 National Health Interview Survey, Lieu et al31 found that black and Hispanic adolescents were more likely than white adolescents to lack a usual source of care and that racial differences in access and utilization persisted after controlling for health insurance and socioeconomic factors. Furthermore, minority youth may be more likely than white youth to seek care through sites other than physician offices.15 ,18 ,19 ,31
The NAMCS does not represent the diverse array of providers serving youth and may therefore underestimate the true utilization of nonemergency ambulatory services by youth. Ryan et al39reported that 27% of nonemergency ambulatory visits by adolescents aged 12 to 18 years took place in settings such as hospital clinics, public health centers, family planning clinics, and school-based clinics. Between the early 1970s and 1994, the number of school-based health centers in the United States increased from one or two to more than 620.17 Despite this impressive growth of a new service model, our estimates indicate that two-thirds of adolescent visits continue to be made to physician offices.
Adolescents who visit physician offices, however, choose different specialists than they did a decade ago. Pediatricians comprised 41.2% of visits by 11- to 14-year-olds in 1994, compared with 29.3% in 1980 to 198128 ,29 and 33.3% in 1985.29 ,40DuRant29 postulated that the change during the 1980s reflected the increasing interest of pediatric professional organizations in adolescent medicine as well as provider incentives to expand their patient populations. This may have been bolstered in the early 1990s with the addition of a special requirement for adolescent medicine training during the 3 years of pediatric residency. Consequently, the deficiencies in pediatrician knowledge, skill, and comfort in adolescent medicine reported in surveys of the 1980s may have improved by 1994.41 ,42
Just as early adolescent visits to pediatricians have increased, so too have mid and late adolescent visits to obstetrician-gynecologists. In 1985, 18.6% of office visits by females aged 15 to 20 years were to obstetrician-gynecologists.29 ,40 In 1994, the rate had climbed to 19.5% for 15- to 17-year-olds and 37.3% for 18- to 21-year-olds. The change almost certainly reflects the increasing rates of sexual activity, pregnancy, and sexually transmitted disease during the late 1980s and early 1990s.6 ,7
Primary care physicians consistently have noted that inadequate time is a deterrent to the provision of preventive services, particularly when dealing with adolescents.43 ,44 We found that the time physicians spent with adolescents in 1994 had increased somewhat since 198540 but had not changed since 1990.45 Given the time constraints faced by most providers in the 1990s, it is not surprising that the mean visit duration was stable across the four specialties that provide primary care as well as across all adolescent age/sex subgroups. The time limitations almost certainly contribute to the uniformly low rates of focused health counseling during office visits by adolescents. The counseling rates have improved since 199045 but remain too low given the prevalence of adverse health outcomes attributable to risk behaviors.
There are important limitations to our study. First, as noted above, the NAMCS data set includes visits to office-based physicians only and does not reflect the utilization of other nontraditional services. This limitation may be especially important when interpreting utilization by minority, underprivileged, or underserved youth. Second, our study is primarily descriptive, intended to provide the reader with a broad overview of office visits use by adolescents. It was not designed to compare the utilization trends of physician offices with those of other service sites. Third, the visit, not the patient, is the unit of measurement. This complicates both comparison with population-based studies and interpretation of the health insurance data. Fourth, this data set is designed to provide estimates through sampling weights and thus limits the investigation of uncommon visit characteristics or the combination of visit characteristics. The integrity of the data is protected through strict release criteria established by the National Center for Health Statistics, and we adhered closely to these criteria in our analyses. Fifth, the NAMCS, like many other surveys, is subject to item nonresponse. Unanswered items were imputed by randomly assigning values from patient record forms with similar characteristics. This may particularly affect data pertaining to race and ethnicity, which had the highest rates of nonresponse (10% and 15%, respectively).
Adolescent utilization of physician offices is low across all three age subgroups and has not increased since the early 1980s. Of particular concern are the exceedingly low visit rates of adolescents who are black, Hispanic, and male. Peak lifetime uninsurance rates repeatedly have been shown to occur during adolescence, even among the select population that seeks nonemergency care. Despite acknowledged risk behaviors yielding poor health outcomes, adolescent visits to physicians are short and counseling is inadequate. As adolescents progress through the second decade of life, their behaviors, problems, providers, and health needs clearly change. Our findings support an age-stratified approach to the study of health services design and utilization.
This work was supported by grants from the Educational Commission for Foreign Medical Graduates and the Craig-Dalsimer Fund. The study was prepared while Dr Slap was a Fellow at the Center for Advanced Study in the Behavioral Sciences, Stanford, California. Financial support for the Fellowship was provided by the Henry J. Kaiser Family Foundation (84R-2459-HPE) and the Carnegie Corporation of New York (Grant B-6346).
- Received October 19, 1998.
- Accepted December 17, 1998.
- Address correspondence to Gail B. Slap, MD, Division of Adolescent Medicine, Department of Pediatrics, Children's Hospital Medical Center, 3333 Burnet Ave, Cincinnati, OH 45229. E-mail:
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- Copyright © 1999 American Academy of Pediatrics