Linking a medical vocabulary to a clinical data model using Abstract Syntax Notation 1.

We have created a clinical data model using Abstract Syntax Notation 1 (ASN. 1). The clinical model is constructed from a small number of simple data types that are built into data structures of progressively greater complexity. Important intermediate types include Attributes, Observations, and Events. The highest level elements in the model are messages that are used for inter-process communication within a clinical information system. Vocabulary is incorporated into the model using BaseCoded, a primitive data type that allows vocabulary concepts and semantic relationships to be referenced using standard ASN. 1 notation. ASN. 1 subtyping language was useful in preventing unbounded proliferation of object classes in the model, and in general, ASN.1 was found to be a flexible and robust notation for representing a model of clinical information.

Reduction of saliva immunoglobulin levels by swim training.

Saliva immunoglobulin A (IgA) and cortisol levels were measured in 21 male members of a major midwestern swim team. Saliva samples were collected before and after training sessions four times during the fall season; the training intensity was light, moderate, heavy and during the taper period before a major competitive meet. Saliva IgA levels were decreased after each training session, reaching statistical significance with the moderate training intensity. Over the 3-month training period the pre-session and post-session IgA levels both decreased significantly during the heavy and taper training intensities later in the fall season. Cortisol levels were significantly elevated only after the heavy-intensity training session. The Profile of Mood States (POMS) was used to assess the swimmers' overall mood on each test day. No significant correlations were found between the global POMS score and IgA or cortisol. Also, cortisol and IgA were not significantly correlated except after the light training session. Results from this study indicate that acute bouts of exercise can reduce salivary IgA levels and that chronic exercise of high intensity can reduce the resting levels of IgA. These changes may render the athletes more vulnerable to respiratory infections after exercise and even at rest during the later stages of the competitive season.

Bacteremic superinfections of patients with bacteremia: occurrence, bacteriology, mortality, and duration of hospitalization at Boston City Hospital during 12 selected years between 1935 and 1972.

During the course of hospitalization of 6,414 patients with bacteremic infections identified at Boston City Hospital (Boston, Massachusetts) during 12 selected years between 1935 and 1972, 6.0% developed verified bacteremic superinfections with organisms not isolated or identified in the primary bacteremic infection. Analysis of these cases reemphasizes the increasing occurrence of serious hospital-acquired infections despite the successive introduction and intensive use of a large number of effective antibacterial agents. The bacteremic superinfections, like the primary hospital-acquired bacteremias, increased in incidence over the years, particularly since 1961; they were more frequent and were associated with a higher mortality rate and longer duration of hospital stay in the primary hospital-acquired cases than in the patients in whom bacteremia was considered to be community-acquired. The organisms in superinfections were similar to those in primary hospital-acquired bacteremias. Superinfection was more frequent among the patients who died than among the survivors.

Duration of hospitalization for bacteremic infections at Boston City Hospital during 12 selected years between 1935 and 1972.

In survivors of both community-acquired (CA) and hospital-acquired (HA) bacteremic infections at Boston City Hospital during 12 selected years between 1935 and 1972, the mean hospital stay fluctuated widely from one selected year to the next, but it was generally shorter and early discharges were more frequent in the years when effective antibacterial agents were used. The greatest reduction in hospital stay occurred by 1941. The size of the fluctuations and reductions also varied with the causative organism. The average duration of hospitalization of all survivors of HA bacteremic infections after the first positive blood culture was 10.5 days longer than the total hospitalization of survivors of CA infections. The reduced length of hospital stay after 1935 is attributed to the successful use of effective antibacterial drugs, and the greater effect in CA than in HA cases is attributed to more frequent infections in the latter with organisms resistant to those drugs.

Duration of hospitalization for acute bacterial empyema at Boston City Hospital during 12 selected years from 1935 to 1972.

The duration of hospitalization for acute bacterial empyema of the pleura was determined for all cases at Boston City Hospital during 12 selected years between 1935 and 1972. Patients whose infection was acquired after admission stayed in the hospital longer than those in whom the empyema, or the infection of which the empyema was a complication, was present at the time of admission. The differences were mostly related to serious underlying disease in the hospital-acquired cases. However, the duration of hospitalization after the empyema was bacteriologically confirmed was not much different in the community-acquired and hospital-acquired cases. Hospital stay was further prolonged in patients whose empyema was superinfected with new bacterial species after the original infecting organisms were determined. Hospitalization was shorter in the 10 selected years between 1974 and 1972, when penicillin and other active antibiotics were used, than in two years before penicillin became available, 1935 and 1941.

Changing ecology of acute bacterial empyema: occurrence and mortality at Boston City Hospital during 12 selected years from 1935 to 1972.

The occurrence, etiology, and demography of acute bacterial empyema are presented to reflect the widespread use of sulfonamides, penicillin, and other active antibiotics. In community-acquired (C-A) cases Streptococcus pneumoniae, hemolytic streptococci, and Staphylococcus aureus were the most frequent single organisms identified in initial positive cultures of pleural fluid during 1935. S. pneumoniae declined steadily until 1953 but continued to occur frequently in C-A cases. Hemolytic streptococci became infrequent. S. aureus increased and became the most frequent organism in 1955 and declined to original levels after 1965 while gram-negative rods increased. S. aureus, aerobic gram-negative rods, and enterococci were most frequent in originally mixed infections, hospital-acquired cases, and superinfections. Anaerobes with or without aerobes were mostly seen in C-A cases and did not vary in incidence. Mortality increased with age. Overall mortality was greater during the 10 antibiotic years, associated with a marked decrease in the proportion of patients younger than 50 years and increase in those over 60 years old, and was greater in patients with serious underlying diseases subjected to more complicated surgical procedures.

Acute bacterial meningitis at Boston City Hospital during 12 selected years, 1935-1972.

Data are presented on the occurrence of and mortality rate from acute bacterial meningitis at Boston City Hospital during 12 years between 1935 and 1972 selected in relation to the introduction of potent antibacterial agents. The most frequent causative organisms were Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae, but large proportions were caused by other gram-positive cocci and gram-negative bacilli. The greatest reduction in mortality rate after antibiotics became widely used was in patients with meningococcal and influenzal meningitis who were less than or equal to 19 years old. Less striking reductions occurred in cases of other etiologies in patients less than or equal to 59 years old, but in those greater than or equal to 60 years old, the mortality rate remained high, and the proportion of cases of meningitis in that age group more than doubled. Comparisons with similar data on all bacteremic infections are presented.

Duration of hospitalization for acute bacterial meningitis at Boston City Hospital during 12 selected years, 1935-1972.

An analysis is presented of the duration of hospitalization of the patients with acute bacterial (purulent) meningitis which occurred at Boston City Hospital during 12 selected years between 1935 and 1972. Considerable differences in the length of stay in the hospital were noted depending on the bacterial etiology, whether the infection was present on admission or acquired within the hospital, and, of course, whether the patient survived or died. Most of the deaths occurred within the first few days after admission or after the diagnosis was first established, but even among fatal cases, the survival time differed depending on the etiology and site of acquisition of the infection. During the years after effective antibiotics became available the hospital stay of patients who survived after admission for meningococcal, influenzal, or pneumococcal meningitis was shorter than before. The same has not been true for meningitis caused by other gram-positive cocci, gram-negative rods, or mixed infections, probably reflecting the relative ineffectiveness of antimicrobial therapy in such patients.

Changes in occurrence of capsular serotypes of Streptococcus pneumoniae at Boston City Hospital during selected years between 1935 and 1974.

The number of patients with pneumococcal bacteremia, empyema, and meningitis at Boston City Hospital during selected years between 1935 and 1974 is reported. The distribution of specific types in the bacteremic patients during each of the selected years and in the various focal infections in all the years is also detailed. The numbers and rates per 1,000 admissions of bacteremic pneumococcal infections and the numbers of cases of pneumococcal meningitis and empyema varied independently over these years and differed from those previously reported for 1929 to 1936. The types most frequent in pneumococcal bacteremias varied over the years, and the distribution of types among them differed markedly from that among the patients with focal infections. Variations in the distribution of pneumococcal types at different times in the same place, in different places, and in various sites of infection may be important in selecting types to include in pneumococcal vaccines for different populations.

Bacteremia at Boston City Hospital: Occurrence and mortality during 12 selected years (1935-1972), with special reference to hospital-acquired cases.

The cases of all patients hospitalized at Boston City Hospital during 1972 who had blood cultures positive for a clinically significant, aerobic bacterial pathogen or for Candida were analyzed with respect to incidence and mortality, sex, age, admission to medical or surgical services, and the causative organism. Similar data were obtained for 11 years between 1935 and 1969 selected to reflect the introduction and general use of various effective antibacterial agents. Comparisons were also made between hospital-acquired bacteremic infections (defined as those in which the first positive blood culture was obtained on or after the third day in the hospital) and community-acquired infections (defined as those with positive blood cultures on admission or within the first two days in the hospital). In 1972, the incidence of bacteremic infections (but not the case-fatality ratio) was significantly higher in males than in females. Bacteremic infections were more than twice as frequent on the medical than on the surgical services, but the case-fatality ratio was slightly but not significantly higher on the surgical services. Bacteremia wasteremia was most frequent in the youngest (birth through nine years) and the oldest (greater than or equal to 60 years) age groups, whereas the case-fatality ratio was lowest in the youngest group and increased with each decade of life. Streptococcus pneumoniae was the most frequent organism causing bacteremia; next were Escherichia coli, Klebsiella-Enterobacter, and Staphylococcus aureus, in that order...