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Biomedical subjects

D H Mark

Publications and source records attributed to D H Mark.

At least 19 recordsLinked to original sources
PubMed1998

In-line skating: use of protective equipment, falling patterns, and injuries.

OBJECTIVE: To determine the use of protective equipment, reasons for nonuse of protective equipment, and patterns of injury, falls, and stopping techniques of recreational in-line skaters. DESIGN: Survey. PARTICIPANTS: 313 in-line recreational skaters observed skating in the parks, on bicycle trails, and on parkways in Milwaukee, Wisconsin and Columbus, Ohio were asked to participate in a short survey in 1995. MAIN OUTCOME MEASUREMENTS: The frequency of in-line skater use of protective equipment, reasons for nonuse, patterns of injury, and patterns of falls. RESULTS: Protective equipment was worn most of the time in the following proportions of skaters [95% confidence interval in brackets]: wrist guards (51%) [44.7%-58.1%]; knee pads (36%) [29.3%-42.5%]; elbow pads (15%) [8.4%-22.8%]; and helmets (15%) [8.0%-22.0%]. Reasons cited for not using protective equipment included lack of perceived need (47.3%), discomfort (37.5%), cost (15.9%), and undesirable appearance (15.2%). Stopping techniques included skating off into the grass (14.6%) [11.8%-17.4%] and voluntarily falling (3.5%) [2.1%-4.9%]. Causes of involuntary falls included spontaneous loss of balance (32.9%) [28.9%-36.9%], hitting rocks or other small objects (17.3%) [14.4%-20.2%], uneven pavement (17%) [14.2%-19.8%], and failure to stop (11.3%) [8.4%-14.2%]. Site of initial impact after falling included the hands and wrists (44.6%) [38.3%-50.9%], the knees (19.6%) [16.4%-22.8%], and the buttocks region (17.2%) [14.3%-20.1%]. Injuries had occurred in 26% of the skaters; 14% of injuries were fractures. CONCLUSIONS: In-line skaters often do not wear protective equipment because they believe it is not necessary. Recent studies have suggested, however, that protective equipment does prevent injuries. Physicians should counsel their patients who are in-line skaters to use protective equipment.

Accidental Falls↗
PubMed1997

The role of dental prostheses in alveolar ridge squamous carcinomas.

BACKGROUND: Alveolar ridge squamous carcinomas develop in patients outside the usual constellation of risk factors. OBJECTIVE: To determine whether the use of dentures was a risk factor specific to patients with alveolar ridge carcinoma. DESIGN: Case-control method with a unique control group-a concurrent cohort of patients with head and neck cancer with primaries in the oropharynx, hypopharynx, and larynx. SETTING: Tertiary care hospital-based clinic. PATIENTS: Forty-one patients with squamous carcinomas centered on the maxillary or mandibular alveolar ridges. The control group was 175 concurrently seen patients with squamous carcinomas of the laryngopharynx for whom dental status was known. MAIN OUTCOME MEASURES: Age at diagnosis, sex, tobacco use, alcohol use, and denture use. RESULTS: Patients with alveolar ridge were more likely to be female, older, nonsmokers, and nondrinkers. The crude odds ratio of denture use in patients with alveolar ridge cancer was 2.28 (P=.03). Eliminating other confounding factors with logistic regression, the adjusted odds ratio dropped to 1.30 (P=.59). Among patients with alveolar ridge, smoking status correlated with age and gender: current smokers were on average 64.4 years old and 9 of 16 were men. Nonsmokers' average age was 79.1 years and 1 of 11 was a man. CONCLUSIONS: In this study, denture use was not an independent risk factor for alveolar ridge carcinomas. Among patients with little to no tobacco or alcohol exposure, the alveolar ridge carcinomas tended to occur in the elderly and in women.

Aged↗
PubMed1997

Interpreting the term selection bias in medical research.

The issue of selection bias is often raised in the critical appraisal of medical studies, but it is often poorly defined and misunderstood. This paper, describes three common patterns of use of the term selection bias and their effects on study results. The three ways in which selection bias is used are related to 1) selection of representative subjects, 2) selection of subjects to exposures, and 3) selection of subjects at outcome. Avoidance of bias in the first of these issues, selection of representative subjects, enhances the ability to generalize a study's results. The other two uses of selection bias relate to the internal validity of studies. The selection of subjects to exposures without randomization in observational studies can distort results because of confounding variables. The selection of study subjects at outcome in case-control and cross-sectional studies can distort study findings if selection into the study is distorted according to exposure status. Readers of medical studies should understand the different implications of these uses to improve their critical evaluation of studies. Writers and discussants should be aware of these differences and provide clarifying details when they use the term.

Case-Control Studies↗
PubMed1997

Serial sevens: not the most effective test of mental status in high school athletes.

OBJECTIVE: To evaluate the ability of uninjured high school athletes to pass three mental status tests that are commonly used on the sidelines for the evaluation of concussions: the serial sevens test, the serial threes test, and recitation of months of year in reverse order (MOYR). PARTICIPANTS: High school student athletes in grades 9, 10, 11, and 12 having sports preparticipation physical examinations. The initial study tested 522 consecutive athletes. The follow-up study tested 109 consecutive athletes. INTERVENTION: The athletes of the initial group were asked to perform a serial sevens test, followed by a serial threes test, and finally to recite the MOYR. The second group was asked to perform the same tests in a random order. MAIN OUTCOME MEASURES: Participants were given 1-min time limits for each test, with passing defined as either 7 consecutive correct iterations or 11 correct with one mistake. RESULTS: For the initial group, 51.3% successfully performed serial sevens, 78.7% successfully performed serial threes, and 89.5% successfully recited the MOYR. For the second group, 52.7% successfully performed serial sevens, 78.1% successfully performed serial threes, and 88.9% successfully recited the MOYR. The pass rates were significantly different for both groups. The pass rates were similar for both sexes, all grade levels, and all sports in both test groups. Participants, both overall and in all subgroups, failed serial sevens more often than serial threes and MOYR (p < 0.001 for the initial group; p < 0.0001 for the second group). They failed serial threes more often than MOYR (p < 0.001 for the initial group; p < 0.01 for the second group). CONCLUSIONS: The percentage of uninjured high school athletes successfully completing serial sevens is too low to make the test useful for evaluation of concussion; the test lacks specificity. The percentage of athletes passing the MOYR was greatest, perhaps making this a better sideline test than the traditional serial sevens test. However, testing needs to be done in injured athletes before clinical application can be recommended.

Adolescent↗
PubMed1996

Medicare costs in urban areas and the supply of primary care physicians.

BACKGROUND: The supply of primary care physicians may be important determinants of health care costs. We examined the association between primary care physician supply and geographic location with respect to variation in Medicare Supplementary Medical Insurance (Part B) reimbursement. METHODS: We performed an analysis of data from all US metropolitan counties. Physician supply data were derived from the American Medical Association Masterfile. Medicare Part B reimbursements and enrollment data came from the Health Care Financing Administration. Physician supply was calculated for family practice, general internal medicine, and non-primary care specialties. Linear regression was used to test the association of physician supply and Medicare costs and to adjust for potential confounding variables. RESULTS: The average Medicare Part B reimbursement per enrollee was $1283. After adjusting for local price differences and county characteristics, a greater supply of family physicians and general internists was significantly associated with lower Medicare Part B reimbursements. The reduction in reimbursements between counties in the highest quintile of family physician supply and the lowest quintile was $261 per enrollee. In contrast, a greater supply of general practitioners and non-primary care physicians was associated with higher reimbursements per enrollee. CONCLUSIONS: These results add to the evidence than an increased supply of primary care physicians is associated with lower health care costs. If this association is causal, it supports the theory that increasing the number of primary care physicians may lower health care costs.

Aged↗
PubMed1995

In-line skating. An observational study of protective equipment used by skaters.

OBJECTIVES: To determine the frequency and patterns of use of the various types of protective equipment by in-line skaters and to determine if use of protective equipment was associated with the age, sex, group composition, or expertise of the skater. DESIGN: A total of 1548 in-line skaters were observed during a 3-month period in Milwaukee, Wis. Identification and protective equipment data were recorded and analyzed by chi 2 tests with Pearson's correlation coefficient. RESULTS: Overall, 491 skaters (31.7%) wore no protective gear. Wrist guards were worn by 999 skaters (64.5%). Helmets were worn by only 40 skaters (2.6%). Overall, adolescent males, children, and advanced skaters were the least likely to be observed wearing protective equipment. CONCLUSIONS: Protective equipment is underused by many in-line skaters. Educating in-line skaters about the value of wearing protective equipment, as recommended by equipment manufacturers, may help reduce the severity or incidence of skating injuries.

Adolescent↗
PubMed1995

Characteristics of residents with do-not-resuscitate orders in nursing homes.

We determined patient characteristics associated with do-not-resuscitate (DNR) status in nursing homes using cross-sectional analysis of secondary data derived from Minimum Data Set documents in 14 nursing homes from one state in the upper Midwest. The primary outcome variable was DNR status. Bivariate analysis was first carried out on all variables. Variables associated with DNR status at this stage were then included in a stepwise logistic regression to determine variables independently associated with DNR status. Overall, 71% of patients had DNR orders. Variables found to be independently associated with a higher probability of DNR status were increasing age, female gender, worse cognitive function, durable power of attorney, being self-paying, or having commercial insurance. Lack of daily contact with relatives and friends and lack of involvement with others were associated with lower probability of DNR status. A higher prevalence of DNR status in nursing homes was seen than in prior literature. The patient characteristics shown to be associated with DNR status may give important insight into the reasons that such decisions are made.

Age Factors↗
PubMed1995

Influences on teaching colposcopy and treatment modalities in family practice programs.

BACKGROUND: Colposcopy and related therapeutic modalities are taught in many family practice residency programs. The role of the following two factors in a family practice residency program's decision to teach these procedures was evaluated: 1) the coexistence of an obstetrics and gynecology (OB-GYN) residency program at the affiliated hospital and 2) the perceived attitude of community obstetrician-gynecologists toward family physicians performing the procedures. METHODS: In 1993, all 399 accredited family practice residency programs were surveyed, with a response rate of 86.5%. RESULTS: Ninety-three percent of responding programs taught colposcopy. All programs that rated community obstetrician-gynecologists' attitudes as positive taught colposcopy, and 91% taught cryotherapy. In programs rating local obstetrician-gynecologists' attitudes as negative, 85.5% taught colposcopy, and 71% taught cryotherapy. A co-located OB-GYN program did not influence a family practice program's likelihood of teaching colposcopy or treatment modalities. CONCLUSION: A perception that community obstetrician-gynecologists have negative attitudes about family physicians performing colposcopy may dissuade some family practice programs from teaching colposcopy and related treatment modalities. This influence was not seen in programs with a co-located OB-GYN residency.

Clinical Competence↗
PubMed1995

Primary care physicians in underserved areas. Family physicians dominate.

Using the definitions of "medically underserved areas" developed by the California Health Manpower Policy Commission and data on physician location derived from a survey of California physicians applying for licensure or relicensure between 1984 and 1986, we examined the extent to which different kinds of primary care physicians located in underserved areas. Among physicians completing postgraduate medical education after 1974, board-certified family physicians were 3 times more likely to locate in medically underserved rural communities than were other primary care physicians. Non-board-certified family and general physicians were 1.6 times more likely than other non-board-certified primary care physicians to locate in rural underserved areas. Family and general practice physicians also showed a slightly greater likelihood than other primary care physicians of being located in urban underserved areas.

California↗
PubMed1994

Mortality of patients after radical prostatectomy: analysis of recent Medicare claims.

A 100% sample of Medicare claims records of patients undergoing radical prostatectomy in 1990 was analyzed for 30-day mortality and 1-year all-cause mortality rates. Overall, there was a 0.5% 30-day mortality and 1.8% 1-year mortality rate. Compared to the general population, mortality was approximately half of expected mortality and close to estimated mortality of elderly men in excellent health. There was no trend of increasing 30-day mortality with patient age, and a modestly increased 1-year mortality rate with increasing age. These results are consistent with improved perioperative survival for all patients compared to analyses performed on data for prior years and selection of healthy patients undergoing radical prostatectomy. These trends improve the potential benefit of radical prostatectomy.

Aged↗
PubMed1994

Students' time allocation in a required third-year ambulatory care clerkship.

PURPOSE: To assess time use by students during clinic sessions of an ambulatory care clerkship. METHOD: All 207 third-year students at the Medical College of Wisconsin during 1991-92 were asked to report their time use in eight categories during two clinic sessions of the three-week clinical component of the required clerkship in ambulatory care medicine. Other variables assessed were site of clinical rotation, first versus third week of rotation, and time of year of rotation. The statistical methods used were t-tests and one-way analysis of variance. RESULTS: Of the 207 students, 192 (93%) completed time-allocation reports for the first and third weeks of their rotations. The average time spent per clinic session was four hours. Compared with the students at faculty practice sites, the students at private practice sites spent significantly more time observing and working with preceptors as they saw patients and significantly less time doing solo clinical work (reviewing and writing in charts). During the course of each rotation, the students increased the time they saw patients by themselves and decreased the time they observed preceptors. As the year progressed, later cohorts of students spent less time observing preceptors and more time working by themselves. CONCLUSION: Both within and across rotations, the students eventually spent less time observing and more time working independently. However, the results suggest that preceptors in private practice may not allow students as much autonomy as do faculty preceptors. Further research is needed to determine (1) whether the differences between types of preceptors result in meaningful differences in the quality of education and (2) which activities or mixes of activities contribute most to students' education.

Ambulatory Care↗
PubMed1994

Influence of demographics and profitability on physician selection of family practice procedures.

BACKGROUND: Family physicians must make complex decisions regarding which procedures to learn in training and which to perform in practice. Factors that influence these decisions include community needs, the potential profitability of a procedure, and the desires and skills of the individual physician. METHODS: To further clarify some of these influences, we surveyed members of the Wisconsin Academy of Family Physicians. The survey instrument included questions about 27 different procedures, including the perceived profitability of the procedure, which procedures they had discontinued, and which they planned to learn. RESULTS: More than 40% of family physicians reported doing skin surgery, flexible sigmoidoscopy, nonstress obstetrical testing, breast-cyst aspiration, multiple joint arthrocentesis, and Norplant insertion, whereas fewer than 6% perform colonoscopy, esophagogastroduodenoscopy, and nasolaryngoscopy. Fifty-seven percent of physicians had discontinued at least one procedure, and 34% planned to learn one or more procedures. Being younger, male, and practicing in smaller communities correlated with performing a greater number of procedures (P < .001), but female physicians performed more gynecologic procedures (P < .05). There was a statistically significant correlation (r = -.478, P < .05) between perceived low profitability of a procedure and family physicians discontinuing a learned procedure, and a marginal correlation between perceived profitability and planning to learn a procedure (r = .338, P < .1). CONCLUSIONS: Family physicians in Wisconsin vary greatly in the number and types of procedures performed. Community size, sex, and age are important variables associated with the number and type of procedures performed. The performance of procedures is dynamic: physicians both discontinue learned procedures and learn new procedures. The profitability of the procedure influences the learning and discontinuation of procedures.

Adult↗
PubMed1993

The effect on resident attitudes of regulatory policies regarding pharmaceutical representative activities.

OBJECTIVE: To determine the effect on resident attitudes of policies regarding pharmaceutical representative interactions with residents. DESIGN: Cross-sectional survey. SETTING: National sample of U.S. family medicine residencies. PARTICIPANTS: Three hundred seventy-eight residents from 14 randomly selected programs. Seven programs had written policies and restrictions (restricted programs), and seven had no such restriction or guideline (free programs). MEASUREMENTS AND MAIN RESULTS: The authors assessed resident attitudes regarding the perception of benefit from pharmaceutical representative activities, the usefulness of various sources of drug information, and the appropriateness of accepting gifts from a pharmaceutical representative. There were 265/378 respondents (70% response rate). Residents from restricted programs reported fewer benefits from pharmaceutical representative interactions and were less likely to feel that acceptance of gifts was appropriate. The amount of exposure to pharmaceutical representatives was positively correlated with perceived benefit and negatively correlated with ratings of appropriateness of gift acceptance. CONCLUSION: Regulatory policies can influence resident attitudes and perceptions. Training programs should develop written policies to help guide resident-pharmaceutical representative interactions.

Attitude of Health Personnel↗