Cigarette acquisition and proof of age among US high school students who smoke.

OBJECTIVE: To determine how US high school students who are under 18 years of age and who smoke obtain their cigarettes and whether they are asked for proof of age. DESIGN AND SETTING: Data from the Centers for Disease Control and Prevention's 1995, 1997, and 1999 national Youth Risk Behavior Surveys which employed national probability samples of students in grades 9-12 (ages 14-18 years). MAIN OUTCOME MEASURES: Associations of usual source of cigarettes and request for proof of age with variables such as sex, race/ethnicity, grade, and frequency of smoking. RESULTS: In 1999, among current smokers under age 18 years, 23.5% (95% confidence interval (CI), -4.5% to +4.5%) usually purchased their cigarettes in a store; among these students, 69.6% (95% CI -5.7% to +5.7%) were not asked to show proof of age. As days of past month smoking increased, reliance on buying cigarettes in a store (p < 0.001) and giving someone else money to buy cigarettes (p < 0.001) increased, and usually borrowing cigarettes decreased (p < 0.001). From 1995 to 1999, relying on store purchases significantly decreased (from 38.7% (95% CI -4.6% to + 4.6%) to 23.5% (95% CI -4.5% to +4.5%)); usually giving someone else money to buy cigarettes significantly increased (from 15.8% (95% CI -3.6% to +3.6%) to 29.9% (95% CI -4.5% to + 4.5%)). CONCLUSIONS: Stricter enforcement of tobacco access laws is needed to support other community and school efforts to reduce tobacco use among youth. Furthermore, effective interventions to reduce non-commercial sources of tobacco, including social, need to be developed and implemented.

Cost-effectiveness of a school-based tobacco-use prevention program.

OBJECTIVE: To determine the cost-effectiveness of a school-based tobacco-use prevention program. DESIGN: Using data from the previously reported 2-year efficacy study of the Project Toward No Tobacco Use (TNT), we conducted a decision analysis to determine the cost-effectiveness of TNT. The benefits measured were life years (LYs) saved, quality-adjusted life years (QALYs) saved, and medical care costs saved, discounted at 3%. The costs measured were program costs. We quantified TNT's cost-effectiveness as cost per LY saved and cost per QALY saved. INTERVENTION: A 10-lesson curriculum designed to counteract social influences and misconceptions that lead to tobacco use was delivered by trained health educators to a cohort of 1234 seventh-grade students in 8 junior high schools. A 2-lesson booster session was delivered to the eighth-grade students in the second year. The efficacy evaluation was based on 770 ninth-grade students who participated in the program in the seventh and eighth grades and in both the baseline and the 2-year follow-up survey. RESULTS: Under base case assumptions, at an intervention cost of $16 403, TNT prevented an estimated 34.9 students from becoming established smokers. As a result, we could expect a saving of $13 316 per LY saved and a saving of $8482 per QALY saved. Results showed TNT to be cost saving over a reasonable range of model parameter estimates. CONCLUSIONS: The TNT is highly cost-effective compared with other widely accepted prevention interventions. School-based prevention programs of this type warrant careful consideration by policy makers and program planners.

Initiation of cigarette smoking and subsequent smoking behavior among U.S. high school students.

BACKGROUND: Most adult smokers report trying their first cigarette before age 18 years. Understanding the impact of smoking initiation at young ages may help public health policy makers and practitioners improve strategies to prevent or delay adolescent cigarette smoking. METHODS: This paper examined age of initiation of cigarette smoking and subsequent patterns of smoking among U.S. high school students 16 years of age and older (N = 13,858). We used data from the 1991-1997 national Youth Risk Behavior Surveys, conducted by the Centers for Disease Control and Prevention. RESULTS: The majority of students 16 years of age and older (60.4%) reported ever having smoked a whole cigarette, and 11.1% initiated smoking at age 10 years or younger. Age of smoking initiation was significantly related to current frequent smoking, daily smoking, and whether students had ever smoked daily. A younger age of smoking initiation was associated with smoking more cigarettes per day than was initiating at an older age. CONCLUSIONS: Delaying the onset of smoking may affect the likelihood of becoming addicted to nicotine and smoking heavily. For students who are already addicted to nicotine, smoking cessation programs are needed.

Early inpatient rehabilitation after elective hip and knee arthroplasty.

CONTEXT: Inpatient rehabilitation after elective hip and knee arthroplasty is often necessary for patients who cannot function at home soon after surgery, but how soon after surgery inpatient rehabilitation can be initiated has not been studied. OBJECTIVE: To test the hypothesis that high-risk patients undergoing elective hip and knee arthroplasty would incur less total cost and experience more rapid functional improvement if inpatient rehabilitation began on postoperative day 3 rather than day 7, without adverse consequences to the patients. DESIGN: Randomized controlled trial conducted from 1994 to 1996. SETTING: Tertiary care center. PARTICIPANTS: A total of 86 patients undergoing elective hip or knee arthroplasty and who met the following criteria for being high risk: 70 years of age or older and living alone, 70 years of age or older with 2 or more comorbid conditions, or any age with 3 or more comorbid conditions. Of the 86 patients, 71 completed the study. INTERVENTIONS: Random assignment to begin inpatient rehabilitation on postoperative day 3 vs postoperative day 7. MAIN OUTCOME MEASURES: Total length of stay and cost from orthopedic and rehabilitation hospital admissions, functional performance in hospitals using a subset of the functional independence measure, and 4-month follow-up assessment using the RAND 36-item health survey I and the functional status index. RESULTS: Patients who completed the study and began inpatient rehabilitation on postoperative day 3 exhibited shorter mean (+/-SD) total length of stay (11.7+/-2.3 days vs 14.5+/-1.9, P<.001), lower mean (+/-SD) total cost ($25891+/-$3648 vs $27762+/-$3626, P<.03), more rapid attainment of short-term functional milestones between days 6 and 10 (36.2+/-14.4 m ambulated vs 21.4+/-13.3 m, P<.001; 4.8+/-0.8 mean transfer functional independence measure score vs 4.3+/-0.7, P<.01), and equivalent functional outcome at 4-month follow-up. CONCLUSION: These data showed that high-risk individuals were able to tolerate early intensive rehabilitation, and this intervention yielded faster attainment of short-term functional milestones in fewer days using less total cost.

Malrotation causing patellofemoral complications after total knee arthroplasty.

Thirty patients with isolated patellofemoral complications after total knee arthroplasty were compared with 20 patients with well functioning total knee replacements without patellofemoral complications. The epicondylar axis and tibial tubercle were used as references on computed tomography scans to measure quantitatively rotational alignment of the femoral and tibial components. The group with patellofemoral complications had excessive combined (tibial plus femoral) internal component rotation. This excessive combined internal rotation was directly proportional to the severity of the patellofemoral complication. Small amounts of combined internal rotation (1 degree-4 degrees) correlated with lateral tracking and patellar tilting. Moderate combined internal rotation (3 degrees-8 degrees) correlated with patellar subluxation. Large amounts of combined internal rotational (7 degrees-17 degrees) correlated with early patellar dislocation or late patellar prosthesis failure. The control group was in combined external rotation (10 degrees-0 degree). The direct correlation of combined (femoral and tibial) internal component rotation to the severity of the patellofemoral complication suggests that internal component rotation may be the predominant cause of patellofemoral complications in patients with normal axial alignment. The epicondylar axis and tibial tubercle are reproducible landmarks which are visible on computed tomography scans and can be used intraoperatively. Using this computed tomography study can determine wether rotational malalignment is present and thus, whether revision of one or both components may be indicated.

Postoperative infection following orthopaedic surgery in human immunodeficiency virus-infected hemophiliacs with CD4 counts < or = 200/mm3.

Human immunodeficiency virus-infected hemophiliacs are at risk for bacterial and opportunistic infections with worsening immunosuppression. Thus, the risk of postoperative infection following orthopaedic surgery is of considerable concern. A survey of United States hemophilia treatment centers was conducted to determine the incidence of postoperative infection in human immunodeficiency virus-positive hemophiliacs with CD4 counts of 200 mm3 or less undergoing orthopaedic surgery. A total of 115 centers from 37 states reported that postoperative infection occurred in 10 (15.1%) of 66 patients undergoing 74 orthopaedic procedures, between several weeks and 5 months following surgery. In five (50%), pre-operative infection preceded postoperative joint infection. Staphylococcus was the most common organism isolated in a prosthetic joint infection, in 6 of 10 (60.0%), and the knee was the most commonly affected joint, in 9 of 10 (90.0%). Joint arthroplasty appeared to have 10 times the risk of nonarthroplasty procedures for postoperative infection (9 of 34 [26.5%] and 1 of 40 [2.5%], respectively, P < .01). Two subjects developed chronic osteomyelitis. The rate of postoperative infection in human immunodeficiency virus-positive hemophiliacs with CD4 counts of 200/mm3 or less appears to be high, when compared with the general population. Early, vigorous treatment should be instituted for suspected infection, antibiotic prophylaxis considered for invasive procedures, and surgical intervention individualized based on the balance of risks and benefits.

Comparison of interface membranes obtained from failed cemented and cementless hip and knee prostheses.

Biochemical and histologic analyses were performed on interface membranes obtained at revision of aseptically loosened hip implants (n = 36) and knee implants (n = 16). Clinical failure occurred sooner in patients with uncemented total hip implants (Group 1) than in patients with cemented implants (Group 2) (p < 0.02). There was no difference in time to revision between the patients with uncemented implants (Group 3) and patients with cemented total knee implants (Group 4). Histologically, more small (< 5 mu) polyethylene particles were found within macrophages and fibroblasts in membranes from Groups 1 and 2. Polyethylene particles from failed total knees (> 10-100 mu) were larger than those from failed total hips. Large polyethylene fragments and foreign-body giant cells were more common in failed knees than failed total hip membranes. Biochemically, proteinase and cytokine activity in the tissue culture supernatant from all groups was higher than in the control tissue (p < 0.01). The activities of stromelysin, prostaglandin E2, interleukin-1 alpha, interleukin-1 beta, and tumor necrosis factor-alpha were higher in Groups 1 and 2 than in Groups 3 and 4 (p < 0.05). These findings support the hypothesis that interface membranes enveloping femoral (hip) and tibial (knee) components of failed total joint implants may promote bone resorption and aseptic loosening. The reason for slower failure of knee implants as compared with hip prostheses may be the lower level of biochemical activity and macrophage density that correlates closely with larger polyethylene particles.

Trends and differentials in mortality from cancers of the oral cavity and pharynx in the United States, 1973-1987.

BACKGROUND: This analysis consisted of an examination of trends and differentials in mortality from cancers of the oral cavity and pharynx in the United States for a recent 15-year period. METHODS: The authors have used national cause-of-death data for the United States and intercensal population estimates to examine mortality from oral and pharyngeal cancers between 1973 and 1987 and to study differentials according to gender, race, and region of residence. RESULTS: The overall mortality rate from these cancers decreased by 19% during the 15-year period, with most of the decline occurring after 1979. Mortality was much higher for men than for women and for blacks than for whites throughout the interval. Despite the overall decline, mortality rates increased among blacks, especially among black men. Mortality was highest in the South Atlantic, New England, and Mid-Atlantic states and lowest in the Mountain states. CONCLUSIONS: The disparity between male and female mortality from oral and pharyngeal cancer stems mainly from differences in the likelihood of developing these cancers, whereas the differences between blacks and whites appears to arise more from differences in survival than in incidence. Different age patterns of mortality for blacks and whites exist, in which mortality among whites, but not among blacks, rises continuously with age. An unexplained finding was that mortality rates were reported to have fallen in recent years, whereas incidence and survival rates have reportedly remained almost unchanged. This apparent inconsistency may have resulted from declines in the incidence of oral and pharyngeal cancers that have been masked by improved detection.

A biochemical, histologic, and immunohistologic analysis of membranes obtained from failed cemented and cementless total knee arthroplasty.

Biochemical, histologic, and immunohistochemical analyses were performed on 34 interface membranes obtained from 33 patients during revision total knee arthroplasty. The membranes had surrounded components of cementless (n = 11) and cemented (n = 23) knee prostheses that were aseptically loose. None of these implant failures was caused by catastrophic polyethylene erosion leading to metal-to-metal contact. The histologic findings were similar in the membranes from cemented and cementless knee components: small polyethylene debris within macrophages and large birefringent polyethylene debris within foreign-body giant cells. Metallic debris was seen in membranes from both groups, but cemented membranes had more polymethylmethacrylate particles and more hyalinization. Intracytoplasmic asteroid bodies were observed in several foreign-body giant cells in both types of membranes. No significant differences were found between the two groups in levels of collagenase, prostaglandin E2 (PGE2), interleukin-1 (IL-1), interleukin-6 (IL-6), or tumor necrosis factor-alpha (TNF-alpha), nor in the population of inflammatory cells stained with IL-1, IL-6, and TNF-alpha antibodies. Membranes that had surrounded components with radiographic evidence of diffuse or localized periprosthetic bone loss released significantly more collagenase, IL-1, IL-6, and TNF than did membranes from components without bone loss. These two groups, however, did not have significantly different PGE2 levels. These findings suggest that polyethylene and metal debris may play a role in macrophage activation and the release of mediators of bone resorption in the membranes surrounding failed cemented and cementless total knee implants.

Determining the rotational alignment of the femoral component in total knee arthroplasty using the epicondylar axis.

The posterior condylar surfaces of the femur are routinely used as the reference for the rotational orientation of the femoral component during most primary total knee arthroplasties. The purpose of this investigation was to identify a clearly discernible, reproducible secondary anatomic axis useful for determining the rotational orientation of the femoral component when the posterior condylar surfaces cannot be used. Seventy-five embalmed anatomic specimen femurs were studied. A surgical epicondylar axis was defined as the line connecting the lateral epicondylar prominence and the medial sulcus of the medial epicondyle. The posterior condylar angle was measured as the angle between the posterior condylar surfaces and the surgical epicondylar axis. Measurement of the posterior condylar angle referenced from the surgical epicondylar axis yielded a mean posterior condylar angle of 3.5 degrees (+/- 1.2 degrees) of internal rotation for males and a mean posterior condylar angle of 0.3 degree (+/- 1.2 degrees) of internal rotation for females. Thus, rotational alignment of the femoral component can be accurately estimated using the posterior condylar angle. The posterior condylar angle, referenced from the surgical epicondylar axis, provides a visual rotational alignment check during primary arthroplasty and may improve alignment of the femoral component at revision.

Neural and vascular injury in total hip arthroplasty.

Complete awareness of the anatomy of the pelvis and proximal femur is required if neurologic and vascular complications are to be avoided following total hip arthroplasty. Avoidance of the anterior quadrants for acetabular screw fixation is critical. Cementing techniques are important, and all acetabular and femoral defects should be bone grafted to avoid inadvertent cement migration. Knowledge of the location of pertinent neural and vascular structures should guide retractor placement. Planned lengthening of an extremity during total hip arthroplasty poses a significant risk to neurologic structures, and SSEP monitoring should be considered. In difficult revision procedures and complex primary total hip arthroplasty, preoperative neural and vascular assessment and SSEP monitoring should be done. With the occurrence of a postoperative nerve palsy, careful review of the procedure should be performed to determine the cause of the injury. In this manner the surgeon can best offer appropriate counseling to the patient as to the likelihood of neurologic recovery.

Congenital pseudarthrosis of the tibia. Long-term follow-up study.

Review of the literature reveals how difficult it is to assess the results of treatment of pseudarthrosis of the tibia. There is disagreement as to when the result can be considered final. This study reviewed the long-term results of treatment to determine if skeletal maturity could be considered the definitive end point of treatment or if the results deteriorate past skeletal maturity. In addition, the effect of neurofibromatosis on pseudarthrosis of the tibia is analyzed. Forty-one patients were reviewed. Only 25 had sufficient follow-up data to be included in this study. Eighteen of the 25 had neurofibromatosis. The results were classified according to criteria developed by Morrissy et al. At skeletal maturity, there were ten good results, three fair results, and three poor results, with nine patients having had amputation. At long-term follow-up evaluation (average 36 years; range five to 62 years), one patient with a fair result had elected amputation. About one half of the patients with neurofibromatosis required amputation. This study suggests that the results at skeletal maturity are reliable indicators of long-term results.