PubMed Health⌕ Search

Biomedical subjects

Timothy L Lash

Publications and source records attributed to Timothy L Lash.

At least 37 records · Page 2Linked to original sources
PubMed2004

The primary care pediatrician's influence on medical student's performance of smoking assessments and counseling.

BACKGROUND: American medical schools lack significant educational programs for teaching medical students about counseling parents and children on smoking prevention and cessation. Thus, the objectives of this study were to describe medical student's self-reported behaviors in the assessment of parents and children's use of tobacco and to compare these practices with well-accepted pediatric activities: injury prevention and developmental assessment. METHODS: Third year medical students in a pediatric clerkship at Boston University, all of whom spend part of their clerkship with pediatricians in their offices, completed six weekly surveys (2001-2002) recording their clinical activities in counseling parents and children about smoking, injury prevention, and performing developmental assessments. RESULTS: Of the 150 third year students completing the pediatric orientation, 108 (72%) completed all six feedback surveys and the general cancer prevention survey. Of the 108 students, 77% completed smoking assessments with at least one family per week during their 6-week clerkship compared with performance of injury prevention (85%, P = 0.09) and developmental assessment (91%, P = 0.006). Among all smoking cessation and prevention recommendations, students were most likely to discourage parents from smoking in the house and least likely to offer tips for parents to counsel their children about smoking. All variables related to primary care pediatricians' role modeling and feedback for optimal tobacco counseling practices were significantly associated with student counseling practice. CONCLUSIONS: Third year medical students were less likely to complete smoking assessments than those for developmental assessment and injury prevention counseling. However, primary care pediatricians' strong expectations and modeling of smoking counseling were uniformly associated with improved self-perceived student performance. Future educational activities should engage the primary care pediatrician preceptors of students completing pediatric rotations.

Adult↗
PubMed2004

Null association between pregnancy termination and breast cancer in a registry-based study of parous women.

Studies suggesting a positive association between pregnancy termination and breast cancer risk have often been of retrospective case-control design, so subject to selection and recall biases. We undertook a registry-based analysis with minimal selection bias and prospective record-based ascertainment of terminations. The source population comprised Massachusetts women with a record of giving birth between 1987 and 1999 in the Massachusetts Vital Statistics Registry. Primary breast cancer cases were 25-55 years old at diagnosis between 1988 and 2000 and had a record of the diagnosis in the Massachusetts Cancer Registry. We matched 3 controls to each case on maternal age, year of giving birth and birth facility. Information on terminations (induced and spontaneous) before the birth of record, the matched factors and potential confounders were collected from the birth certificate. After adjustment for the matched factors, age, parity and maternal and paternal education, the odds ratio associating any termination history with breast cancer risk equaled 0.91 (95% CI = 0.79-1.05). The marginally protective adjusted odds ratio largely derived from a protective effect among women with parity equaled to 1 (OR for any termination = 0.68; 95% CI = 0.45-1.03), suggesting a protective effect of terminated pregnancy among women with one live birth.

Abortion, Induced↗
PubMed2004

Tamoxifen and cataracts: a null association.

BACKGROUND: Previous studies have reported an increased risk of cataract for breast cancer patients treated with tamoxifen. We assessed whether breast cancer patients treated with tamoxifen were at increased risk of developing cataracts compared to women not prescribed tamoxifen. METHODS: We used a nested, matched case-control study design and data collected in the General Practice Research Database. We identified all women 30-79 years old who were diagnosed with breast cancer and treated with tamoxifen within 6 months, or with bladder cancer, colorectal cancer or non-melanoma skin cancer between January 1991 and December 1999. From this population, we identified all newly diagnosed cases of cataract. We matched four female controls to each case on age (+/- 1 year), index date and study entry date (+/- 6 months). We assessed the risk of cataracts for current, past and ever users of tamoxifen and according to cumulative use of tamoxifen. We calculated adjusted odds ratios (AOR) and 95% confidence intervals (CI) controlling the matching factors and adjusting for important cataract risk factors. FINDINGS: Current tamoxifen users were at no increased risk of cataract (AOR = 1.0, 95% CI: 0.7, 1.4). There was no evidence of an increased risk with increasing cumulative dose. INTERPRETATION: We detected no increased risk of cataract among breast cancer patients who were treated with tamoxifen compared to women with other cancers who were not prescribed tamoxifen.

Adult↗
PubMed2003

Breast cancer in older women: quality of life and psychosocial adjustment in the 15 months after diagnosis.

PURPOSE: We examined the health-related quality of life (QOL) of a cohort of older women with breast cancer after their diagnosis. PATIENTS AND METHODS: Six hundred ninety-one women aged 65 years and older were interviewed approximately 3 months after breast cancer surgery and two additional times in the following year using standardized QOL measures. Demographic factors, breast cancer treatments, and comorbid conditions were used to model ratings of health-related QOL over time. Self-perceived health and psychosocial adjustment at 15 months after surgery were modeled. RESULTS: Physical and mental health scores declined significantly in the follow-up year, independent of age. However, a cancer-specific psychosocial instrument showed significant improvement in scores. Better 3-month physical and mental health scores, as well as better emotional social support, predicted more favorable self-perceived health 15 months after surgery. Psychosocial adjustment at 15 months was significantly predicted by better mental health, emotional social support, and better self-rated interaction with health care providers assessed at 3 months. CONCLUSION: Contrary to reports from younger women with breast cancer, we observed significant declines in the physical and mental health of older women in the 15 months after breast cancer surgery, whereas scores on a cancer-specific psychosocial QOL measure improved over time, consistent with patterns in younger women. Predictive models indicate that older women with impaired physical functioning, mental health, and emotional social support after surgery have poorer self-perceived health and psychosocial adjustment 1 year later. Interventions to address the physical and emotional needs of older women with breast cancer should be developed and evaluated to determine their impact on subsequent health-related QOL.

Adaptation, Psychological↗
PubMed2003

Multiple informants: a new method to assess breast cancer patients' comorbidity.

Past assessments of comorbidity indices have sought to recommend a single index that performs better than others. The authors used a multiple informants approach as an alternative method to simultaneously assess five indices of comorbidity. This approach provides a single estimate of the overall effect of comorbidity and evaluates the relation any individual index has to the outcomes of interest. Association of comorbidity with definitive primary therapy, discussion of tamoxifen, and receipt of tamoxifen was evaluated in a cohort of 830 older breast cancer patients enrolled at four geographically distinct centers in the United States from 1996 to 1999. The estimated adjusted effect of a unit increase in comorbidity on the odds of discussing tamoxifen therapy was 0.70 (95% confidence interval: 0.56, 0.88). An increase in comorbidity was not associated with receipt of definitive primary therapy (odds ratio = 0.94, 95% confidence interval: 0.79, 1.13) or receipt of tamoxifen (odds ratio = 0.96, 95% confidence interval: 0.72, 1.27). The multiple informants regression proved superior to separate regression models that included only one index. In analyses that require comorbidity adjustment and for which no single index is expected to be ideal, the multiple informants approach is an attractive alternative to selecting a single index and to other methods of using multiple indices.

Aged↗
PubMed2003

A null association between smoking during pregnancy and breast cancer using Massachusetts registry data (United States).

OBJECTIVE: An earlier investigation reported a five-fold increase in breast cancer risk among women who smoked during pregnancy. Using a similar design, we re-examined this hypothesis. METHODS: The source population comprised Massachusetts residents who gave birth between 1987 and 1999 with a birth record in the Massachusetts Vital Statistics Registry. Cases were diagnosed with breast cancer between 1988 and 2000 at ages 25-55 with a record in the Massachusetts Cancer Registry. Three controls were matched to each case on maternal age, year of giving birth, and birth facility. Information on smoking, the matched factors, and potential confounders were collected from the birth certificate. The data were analyzed using conditional logistic regression. RESULTS: After adjusting for potential confounders, women who smoked during pregnancy did not have an increased risk of breast cancer compared to women who did not smoke during pregnancy (relative risk = 1.0, 95% Confidence interval CI = 0.81-1.2). We observed no dose response relation between number of cigarettes smoked per day during pregnancy and breast cancer risk. There was no evidence that our results were biased by misclassification from women inaccurately reporting their smoking status. CONCLUSION: In contrast to the previous study, we did not observe an increased risk of breast cancer in women who smoked during pregnancy.

Adult↗
PubMed2003

Semi-automated sensitivity analysis to assess systematic errors in observational data.

BACKGROUND: Published epidemiologic research usually provides a quantitative assessment of random error for effect estimates, but no quantitative assessment of systematic error. Sensitivity analysis can provide such an assessment. METHODS: We describe a method to reconstruct epidemiologic data, accounting for biases, and to display the results of repeated reconstructions as an assessment of error. We illustrate with a study of the effect of less-than-definitive therapy on breast cancer mortality. RESULTS: We developed SAS code to reconstruct the data that would have been observed had a set of systematic errors been absent, and to convey the results. After 4,000 reconstructions of the example data, we obtained a median estimate of relative hazard equal to 1.5 with a 95% simulation interval of 0.8-2.8. The relative hazard obtained by conventional analysis equaled 2.0, with a 95% confidence interval of 1.2-3.4. CONCLUSIONS: Our method of sensitivity analysis can be used to quantify the systematic error for an estimate of effect and to describe that error in figures, tables, or text. In the example, the sources of error biased the conventional relative hazard away from the null, and that error was not accurately communicated by the conventional confidence interval.

Bias↗
PubMed2002

Advanced age and adjuvant tamoxifen prescription in early-stage breast carcinoma patients.

BACKGROUND: Adjuvant tamoxifen is recommended for all women with estrogen receptor-positive breast carcinoma without regard for age. We investigated age-dependent variations in adjuvant tamoxifen prescription patterns in a cohort of women 80 years of age and older. METHODS: We studied 92 women diagnosed at four U.S. sites with primary, early-stage breast carcinoma. Each woman consented to a medical record review and participated in two telephone interviews. We compared the proportion of tamoxifen prescriptions received by women 85-92 years of age with those received by women 80-84 years of age. Relative risks (RR) and 95% confidence intervals (95% CI) were generated using generalized estimating equations. Confounding by demographic, disease, and treatment characteristics was assessed. RESULTS: Before adjustment, patients 85-92 years of age were 28% less likely to receive a tamoxifen prescription compared with patients 80-84 years of age (RR = 0.72, 95% CI 0.57-0.91). In this sample, patients not prescribed tamoxifen had substantially more comorbidity. After adjusting the crude finding for comorbidity, the RR was 0.74 (95% CI 0.58-0.93). In addition, the oldest patients and those not prescribed tamoxifen were significantly less likely to be married or have living children. After adjusting the crude finding for these two factors, the RR was 0.75 (95% CI 0.59-0.95). There was no confounding by the other demographic, disease, or treatment covariates assessed. CONCLUSION: Given the increasing longevity of the oldest old, undertreatment with adjuvant tamoxifen may put older breast carcinoma patients at an increased risk of disease recurrence and breast carcinoma mortality.

Age Factors↗
PubMed2002

Adjuvant tamoxifen prescription in women 65 years and older with primary breast cancer.

PURPOSE: We examined patterns of adjuvant tamoxifen discussion and prescription among breast cancer patients age 65 years and older. METHODS: We selected from women diagnosed with primary breast cancer those with (1) stage I (tumor diameter > or = 1 cm), stage II, or stage IIIa disease; (2) age 65 years or older on the date of diagnosis; and (3) permission from the attending physician to contact. Data were collected from consenting patients' medical records, telephone interviews with patients, and mailed questionnaires completed by their physicians. RESULTS: We obtained medical record and interview data for 698 patients. The oldest patients (odds ratio [OR], 0.45; 95% confidence interval [CI], 0.23 to 0.87 for those aged 80+ relative to those aged 65 to 69 years old), those with more comorbid conditions (each additional comorbid condition reduced the odds of discussion by 0.84; 95% CI, 0.73 to 0.96), and those who were estrogen receptor-negative (OR, 0.56; 95% CI, 0.32 to 0.99) were less likely to report discussion of tamoxifen therapy with a physician. Older patients (OR, 2.17; 95% CI, 1.18 to 4.01 for 70- to 79-year-olds relative to 65- to 69-year-olds; OR, 2.44; 95% CI, 1.11 to 5.34 for those aged 80+ relative to those aged 65 to 69 years old), those who reported a greater influence of information about tamoxifen on decision-making (an increase in 1 SD increased the odds by 7.43; 95% CI, 4.36 to 12.65), and those whose physicians believed that the benefits of tamoxifen outweighed its risks (an increase in 1 SD increased the odds by 1.87; 95% CI, 1.34 to 2.62) were more likely to be prescribed tamoxifen. CONCLUSION: These findings highlight the key role of communication in the care of older women with breast cancer and its ultimate influence on the receipt of therapy.

Age Factors↗
PubMed2002

What's wrong with the National Ambient Air Quality Standard (NAAQS) for fine particulate matter (PM(2.5))?

Associations between airborne concentrations of fine particulate matter (PM(2.5)) and mortality rates have been investigated primarily by ecologic or semiecologic epidemiology studies. Many investigators and regulatory agencies have inferred that the weak, positive association often observed is causal, that it applies to all forms of airborne PM(2.5), and that current ambient levels of PM(2.5) require reduction. Before implementing stringent regulations of ambient PM(2.5), analysts should pause to consider whether the accumulated evidence is sufficient, and sufficiently detailed, to support the PM(2.5) National Ambient Air Quality Standard. We take two tacks. First, we analyze the toxicologic evidence, finding it inconsistent with the notion that current ambient concentrations of all forms of fine particulate matter should affect pulmonary, cardiac, or all-cause mortality rates. More generally, we note that the thousands of forms of PM(2.5) are remarkably diverse, yet the PM(2.5) NAAQS presumes them to be identical toxicologically, and presumes that reducing ambient concentrations of any form of PM(2.5) will improve public health. Second, we examine the epidemiologic evidence in light of two related examples of semiecologic associations, examples that both inform the PM-mortality association and have been called into question by individual-level data. Taken together, the toxicologic evidence and lessons learned from analogous epidemiologic associations should encourage further investigation of the association between particulate matter and mortality rates before additional regulation is implemented, and certainly before the association is characterized as causal and applicable to all PM(2.5).

Air Pollutants↗
PubMed2002

A null association between active or passive cigarette smoking and breast cancer risk.

The effect of smoking on breast cancer risk has been null in large, well-conducted cohort studies. In a previous study, we stratified the population into active smokers, passive smokers, and never-active never-passive smokers and modeled early life cigarette smoke exposures as causal and later life cigarette smoke exposure as preventive. We observed a complex association between cigarette smoke and breast cancer risk. Using a similar design and population, this study did not confirm the earlier result. Neither ever-active smoking (adjusted odds ratio (OR) = 0.72, 95% confidence intervals (CI) 0.55-0.95) nor ever-passive smoking (adjusted OR = 0.85, 95% CI 0.63-1.1) were strongly associated with breast cancer risk compared with never-active never-passive smoking. No patterns of effects were observed in subgroup analyses.

Breast Neoplasms↗
PubMed2002

Fat depot origin affects adipogenesis in primary cultured and cloned human preadipocytes.

Fat distribution varies among individuals with similar body fat content. Innate differences in adipose cell characteristics may contribute because lipid accumulation and lipogenic enzyme activities vary among preadipocytes cultured from different fat depots. We determined expression of the adipogenic transcription factors peroxisome proliferator activated receptor-gamma (PPAR-gamma) and CCAAT/enhancer binding protein-alpha (C/EBP-alpha) and their targets in abdominal subcutaneous, mesenteric, and omental preadipocytes cultured in parallel from obese subjects. Subcutaneous preadipocytes, which had the highest lipid accumulation, glycerol-3-phosphate dehydrogenase (G3PD) activity, and adipocyte fatty acid binding protein (aP2) abundance, had highest PPAR-gamma and C/EBP-alpha expression. Levels were intermediate in mesenteric and lowest in omental preadipocytes. Overexpression of C/EBP-alpha in transfected omental preadipocytes enhanced differentiation. The proportion of differentiated cells in colonies derived from single subcutaneous preadipocytes was higher than in mesenteric or omental clones. Only cells that acquired lipid inclusions exhibited C/EBP-alpha upregulation, irrespective of depot origin. Thus regional variation in adipogenesis depends on differences at the level of transcription factor expression and is a trait conferred on daughter cells.

Adipocytes↗
PubMedDate not supplied

Long-term follow-up of upper-body function among breast cancer survivors.

We enrolled a cohort of 303 stage I or stage II breast cancer patients diagnosed in Boston, MA, between October 1992 and December 1995. We followed the patients by interview and medical record abstract for 5 years (a) to characterize the incidence and predictors of upper-body function decline and (b) to characterize the incidence and predictors of recovery of upper-body function. The incidence of decline in the first year after therapy (17.7/100 person years) was substantially higher than in the subsequent 4 years of follow-up (11.0/100 person-years, p value for test of homogeneity equal 0.028). With only one exception, no patient characteristic, therapy component, or disease trait was associated with decline over the full follow-up period. Women with less than a high school education had an adjusted relative hazard of decline of 2.3 (95% CI, 1.4-3.7) compared with women with a high school education or more, possibly reflecting occupational or environmental insults that predispose to functional impairment. Women who had reported a decline in upper-body function and who subsequently saw their breast cancer specialist were 4.8-fold more likely to report that they had recovered their upper-body function at their next interview (95% CI, 2.0, 12). This finding suggests that attention to upper-body function during follow-up visits may facilitate recovery.

Activities of Daily Living↗