Serologic evidence of chlamydial and mycoplasmal pharyngitis in adults.

In a study of 763 adult patients we found serologic evidence of infection (a fourfold increase in antibodies) with Chlamydia trachomatis in 20.5 percent of the patients and with Mycoplasma pneumoniae in 10.6 percent, but with group A streptococcus (by culture) in only 9.1 percent. Pharyngitis, the most common problem for which patients seek medical care in the United States, may be caused by nonviral, potentially treatable organisms more often than had been suspected.

Management strategies for urinary and vaginal infections.

Detailed history, physical examination, laboratory and follow-up data were obtained from 821 women coming to a primary care clinic over a two-year period with the symptoms of urinary tract (UTI) or vaginal infection. Using all available information, each patient retrospectively was given one of several mutually exclusive diagnoses. Vaginitis without UTI was diagnosed in 70% of patients, UTI without vaginitis in 12%, UTI and vaginitis in 2%. The conditional probability of the several possible diagnoses was calculated, given various combinations of clinical data; a diagnosis of vaginitis was twice as likely as a diagnosis of UTI in a patient with dysuria. On the basis of these calculations we identified efficient clinical strategies for when to perform a pelvic examination, a urinalysis, and a urine culture, and when to diagnose UTI presumptively on the basis of urinalysis.

Topical v systemic agent treatment for papulopustular acne. A cost-effectiveness analysis.

We used cost-effectiveness analysis to compare the costs, risks, and benefits of two strategies for clearing papulopustular acne; topical therapy alone as initial therapy or a combination of systemic antibiotics and topical agents used at the first visit. Patients treated with combination therapy had fewer weeks of morbidity from acne, and lower dollar costs but have a greater risk of side effects. If the topical therapy alone was chosen to reduce the risk of side effects in a population of patients there would be an additional $764 in costs and 238 weeks of morbidity from acne to avert a single additional instance of side effects. Initial treatment of papulopustular acne with combined oral antibiotics and topical agents thus seems to be cost-effective. After clearing is achieved, maintenance therapy with topical agents should be considered.

Diagnosis and treatment of dyspepsia. A cost-effectiveness analysis.

Dyspepsia is a common problem in ambulatory care. While many authorities recommend ordering upper gastrointestinal x-ray series (UGI) before therapy, there is evidence that clinicians frequently treat dyspepsia without diagnostic procedures. Decision analysis was performed to select optimal management based on probabilities and outcome values from the published literature. The choices evaluated were Symptomatic Therapy (low dose antacids or anticholinergics), Ulcer Therapy (high dose antacids or cimetidine), or UGI followed by further tests or therapy. Our model indicates that mortality is minimized if UGI is performed prior to selection of therapy, and if endoscopy is performed when the x ray shows gastric ulcer. Weeks of pain are minimized if Ulcer Therapy is begun immediately, but direct health care costs are minimized by beginning with Symptomatic Therapy. The marginal cost per additional life saved by performing a UGI rather than beginning with Ulcer Therapy was +1.6 million to +2.3 million, depending on whether endoscopy followed the finding of gastric ulcer. Mortality advantages of the strategies beginning with UGI were sensitive to assumptions regarding the incidence of gastric cancer and the benefits of early diagnosis. With slight reductions in these base case values, the Ulcer Therapy strategy appeared to minimize all outcomes except dollar cost.

Strategies for diagnosing vaginitis.

Detailed history, physical examination, laboratory, and follow-up data were obtained from 821 patients presenting to a primary care clinic over an 18-month period with the symptoms of vaginal infection or urinary tract infection (UTI). Information useful in deciding when to perform a vaginal examination, when to obtain various types of cultures, and when to perform microscopic examination of a saline suspension or Gram stain is presented. Of particular interest were the findings that patients with dysuria more commonly have vaginitis than UTI, the superiority of a saline examination to other means of diagnosing yeast vaginitis, and the rarity of a positive trichomonas preparation when the vaginal discharge had a curd-like appearance.

LAMP. A data management and analysis system for patient registries and clinical studies.

A computer system for the management and analysis of clinical data is described. The system is implemented in the ANSI standard MUMPS language and runs on popular minicomputers. The system is designed to allow clinical investigators or research assistants to define a data base, enter and edit data, produce patient-specific reports, and perform a variety of analyses on user-specified groups of subjects. Programmer intervention is not required at any stage of the management or analysis process, and on-line documentation provides a friendly environment for inexperienced users.

Prevalence of pharyngeal gonorrhea in general medical patients with sore throats.

The prevalence of pharyngeal gonorrhea was investigated in a previously unstudied population: adult patients seeking care for sore throats and other symptoms of respiratory infection in general medical practices. The complaint of sore throat accounts for at least 15 million patient visits each year in the United States. A prospective study of 239 patients in three different settings revealed prevalences of 1% (95% confidence interval of 0.1-3%) in the 192 patients with sore throats, and of zero (95% confidence interval of zero to 3.4%) in 47 patients with respiratory infection symptoms other than sore throat. The data support the position that routine pharyngeal culturing for Neisseria gonorrhoeae for patients who have sore throats is not cost-efficient.

Yield of routine annual laboratory screening in the institutionalized elderly.

We examined the yield of a battery of 19 screening laboratory tests performed routinely in 70 functionally intact patients, averaging 82.6 years of age and residing at a chronic care facility. The 70 patients underwent 3,903 screening tests (70 admission batteries and 156 batteries at annual intervals). Twenty per cent of the admission test results and 17 per cent of all subsequent annual test results were "abnormal". "New abnormal" results (previously unknown to the responsible physicians) occurred primarily in five of the 19 screening tests; they were found in 13 per cent of all admission screening tests and in 6 per cent of all annual tests. However, many of the "new abnormalities" were only minimally outside the normal range, and only 26 (0.7 per cent) led to further diagnostic evaluation. Of these 26, only four (0.1 per cent of all tests ordered) led to changes in patient management, none of which benefited the patient in an important way.

Protocols in ambulatory care.

Protocols offer a mechanism for bringing together two major trends in outpatient care. The first trend is the delegation of certain clinical tasks and responsibilities to health workers other than physicians, and to patients themselves. The second trend is the movement toward standard-setting, peer review, audit and quality assurance, and cost-effectiveness of medical practices. Most of the studies of the use of protocols have been with nurse practitioners, physician assistants, office nurses, and health workers. These studies indicate that non-physicians using protocols - in comparison with physicians using traditional methods - give care that is equally thorough, and that leads to comparably accurate diagnosis treatment, and appropriate referral to physicians. Additionally, health workers guided by protocols achieve relief of patients; symptoms and patient satisfaction, and provide care that is efficient in terms of practitioner time, medication, and test ordering. Consequently, health workers using protocols can reduce the cost of care. Protocols have been developed for use in out-patient areas in both developed and developing nations. Protocosl can also be easily audited as part of a quality assurance program, effecting even further saving in costly provider time.

Efficiency and cost of primary care by nurses and physician assistants.

We conducted a prospective study in a prepaid primary-care practice (health-maintenance organization) of a system in which nurses and physician assistants used protocols, and compared the efficiency and costs of this "new-health-practitioner" protocol system to a physician-only nonprotocol system. In five months, we studied 472 patients with any of four common acute complaints--respiratory infections, urinary and vaginal infections, headache, and abdominal pain; a subset of 203 patients was randomly allocated between the two systems. In the new-health-practitioner system physician time per patient was reduced by 92 per cent, from 11.8 to 0.9 minutes, and average visit costs--including practitioner time and charges for laboratory tests and medications--were 20 per cent less (P = 0.01). We conclude that this protocol system saves physician time and reduces costs.

Cholesterol reduction and life expectancy. A model incorporating multiple risk factors.

In deciding whether to undertake a dietary program to reduce serum cholesterol levels, a person must consider how much benefit to expect. We developed a model that assumes cholesterol reduction is effective and safe in reducing the risk for death from ischemic heart disease. In the model, we considered asymptomatic adults with total serum cholesterol levels between 180 and 300 mg/dL. We defined risk status on the basis of blood pressure, smoking habit, and high-density-lipoprotein cholesterol level. For persons aged 20 to 60 years who are at low risk, we calculate a gain in life expectancy of 3 days to 3 months from a lifelong program of cholesterol reduction. For persons who are at high risk, the calculated gain ranges from 18 days to 12 months. Knowledge of the magnitude of the calculated benefits in increased life expectancy afforded by cholesterol reduction can assist persons in making decisions about dietary change.

Protocol management of male genitourinary infections.

As part of a demonstration study, 567 male patients presenting to a "walk-in" clinic with common genitourinary complaints were interviewed by health assistants guided by a protocol. Independent examination of 19 patients by a health assistant and a physician formally demonstrated that the health assistants could collect the clinical data accurately. Forty-four patients were then randomly chosen to be examined, diagnosed and treated either by a health assistant guided by the protocol and supported by an available physician, or only by a physician. Using medical records and a follow-up interview, we assessed the thoroughness of the medical record, adequacy of diagnosis and treatment, symptom relief, patient satisfaction and patient education: the health assistant-protocol system proved as safe and effective as the MD-only system, and the health assistants were able to manage 68% of patients without involving the physician. The study suggests that briefly-trained health assistants may help save physician and nurse time, and that the development of protocols can help set standards for the medical management of defined problems while providing a mechanism for rapidly creating a complete medical record which can be easily audited for conformance with standards.

Heterophil antibody in adults with sore throat: frequency and clinical presentation.

We studied the prevalence and the clinical and laboratory findings of infectious mononucleosis in ambulatory adult patients with the presenting symptom of sore throat. Extensive clinical data, heterophil antibody test, and differential leukocyte count were obtained prospectively for 709 patients, aged 16 to 73 years, seen in four primary care settings. Heterophil tests were positive in 15 of 709 patients (2%); four of the 15 had greater than 10% atypical lymphocytes. No heterophil-negative patient had greater than 10% atypical lymphocytes. Heterophil-positive patients had mild disease; none was older than 40 years. Of 70 symptoms and signs evaluated, four were found significantly more often (p less than 0.005 for each) in the heterophil-positive patients: palatine petechiae, posterior auricular adenopathy, marked axillary adenopathy, and inguinal adenopathy. If any of these four easily shown physical findings was present, the likelihood of the patient having heterophil antibody was considerably increased; if absent, the probability of infectious mononucleosis was so low that not ordering a heterophil test or differential leukocyte count would have been efficient and safe.

Forecasting coronary heart disease incidence, mortality, and cost: the Coronary Heart Disease Policy Model.

A computer simulation model was developed to project the future mortality, morbidity, and cost of coronary heart disease (CHD) in the United States population. The model contains a demographic-epidemiologic (DE) submodel, which stimulates the distribution of coronary risk factors and the conditional incidence of CHD in a demographically evolving population; a "bridge" submodel, which determines the outcome of the initial CHD event; and a disease history (DH) submodel, which simulates subsequent events in persons with a previous CHD event. The user of the model may simulate the effects of interventions, either preventive (i.e., risk factor modification) or therapeutic, upon mortality, morbidity, and cost for up to a 30-year period. If there were no future changes in risk factors or the efficacy of therapies after 1980, baseline projections indicate that the aging of the population, and especially the maturation of the post-World War II baby-boom generation, would increase CHD prevalence and annual incidence, mortality, and costs by about 40-50 per cent by the year 2010. Unprecedented reductions in risk factors would be required to offset these demographic effects on the absolute incidence of CHD. The specific forecasts could be inaccurate, however, as a consequence of erroneous assumptions or misestimated baseline data, and the model awaits validation based on actual future data.

The prediction of streptococcal pharyngitis in adults.

The usefulness of clinical and laboratory findings for prediction of the presence of Group A streptococci on throat culture and of an increase in antistreptococcal antibodies was investigated in 693 adult patients. Several findings were shown to increase the likelihood of streptococcal isolation, alone and in combination: tonsillar exudate, tonsillar enlargement, tender anterior cervical adenopathy, myalgias, and a positive throat culture in the preceding year. Compared with a frequency of 9.7% in all patients, the probabilities of a positive culture were quite different (ranging from 2 to 53%) in subgroups of patients with different combinations of these clinical findings. The results of a leukocyte count and measurement of C-reactive protein added little additional predictive information. While clinical findings can never predict perfectly the results of a throat culture, they nevertheless can provide useful information--particularly in tending to "rule out" streptococcal infection--in adult patients with pharyngitis.