All Publications

  • Effectiveness of ambulation to prevent venous thromboembolism in patients admitted to hospital: a systematic review. CMAJ open Lau, B. D., Murphy, P., Nastasi, A. J., Seal, S., Kraus, P. S., Hobson, D. B., Shaffer, D. L., Holzmueller, C. G., Aboagye, J. K., Streiff, M. B., Haut, E. R. 2020; 8 (4): E832–E843


    Patient ambulation is frequently recommended to help prevent venous thromboembolism during hospital admission. Our objective was to synthesize the evidence for ambulation as a prophylaxis for venous thromboembolism in hospital.We conducted a systematic review. We searched MEDLINE, Embase, Scopus, Web of Science and Cochrane Central Register of Controlled Trials indexed from their inception through April 2020 for studies of adult patients admitted to hospital, in which ambulation or mobilization alone or concomitant with prophylaxis was indicated for prevention of venous thromboembolism. We searched for unpublished trials. We included randomized controlled trials (RCTs) and observational studies. Two reviewers independently screened articles and assessed risk of bias using 2 validated tools. We scored studies on quality of reporting, internal and external validity and study power; combined scores determined the overall quality.Eighteen articles met the inclusion criteria: 8 retrospective and 2 prospective cohorts, 7 RCTs and 1 secondary analysis of an RCT. The intervention (ambulation or mobilized) groups varied across studies. Five studies examined exercise as a therapeutic prophylaxis for thrombosis and 9 described an ambulation protocol. Five studies attempted to quantify amount and duration of patient ambulation and 3 reported ambulation distance. In the 5 studies rated as good or excellent statistical quality, findings were mixed. Incidence of venous thromboembolism was lowest when pharmacologic anticoagulants were added as part of the prescribed prophylaxis regimen.We did not find high-quality evidence supporting ambulation alone as an effective prophylaxis for venous thromboembolism. Ambulation should not be considered an adequate prophylaxis for venous thromboembolism, nor as an adequate reason to discontinue pharmacologic prophylaxis for venous thromboembolism during a patient's hospital admission.

    View details for DOI 10.9778/cmajo.20200003

    View details for PubMedID 33293333

  • Breast Cancer Screening and Social Media: a Content Analysis of Evidence Use and Guideline Opinions on Twitter. Journal of cancer education Nastasi, A., Bryant, T., Canner, J. K., Dredze, M., Camp, M. S., Nagarajan, N. 2017


    There is ongoing debate regarding the best mammography screening practices. Twitter has become a powerful tool for disseminating medical news and fostering healthcare conversations; however, little work has been done examining these conversations in the context of how users are sharing evidence and discussing current guidelines for breast cancer screening. To characterize the Twitter conversation on mammography and assess the quality of evidence used as well as opinions regarding current screening guidelines, individual tweets using mammography-related hashtags were prospectively pulled from Twitter from 5 November 2015 to 11 December 2015. Content analysis was performed on the tweets by abstracting data related to user demographics, content, evidence use, and guideline opinions. Standard descriptive statistics were used to summarize the results. Comparisons were made by demographics, tweet type (testable claim, advice, personal experience, etc.), and user type (non-healthcare, physician, cancer specialist, etc.). The primary outcomes were how users are tweeting about breast cancer screening, the quality of evidence they are using, and their opinions regarding guidelines. The most frequent user type of the 1345 tweets was "non-healthcare" with 323 tweets (32.5%). Physicians had 1.87 times higher odds (95% CI, 0.69-5.07) of providing explicit support with a reference and 11.70 times higher odds (95% CI, 3.41-40.13) of posting a tweet likely to be supported by the scientific community compared to non-healthcare users. Only 2.9% of guideline tweets approved of the guidelines while 14.6% claimed to be confused by them. Non-healthcare users comprise a significant proportion of participants in mammography conversations, with tweets often containing claims that are false, not explicitly backed by scientific evidence, and in favor of alternative "natural" breast cancer prevention and treatment. Furthermore, users appear to have low approval and confusion regarding screening guidelines. These findings suggest that more efforts are needed to educate and disseminate accurate information to the general public regarding breast cancer prevention modalities, emphasizing the safety of mammography and the harms of replacing conventional prevention and treatment modalities with unsubstantiated alternatives.

    View details for DOI 10.1007/s13187-017-1168-9

    View details for PubMedID 28097527

  • Pre-Kidney Transplant Lower Extremity Impairment and Post-Kidney Transplant Mortality. American journal of transplantation : official journal of the American Society of Transplantation and the American Society of Transplant Surgeons Nastasi, A. J., McAdams-DeMarco, M. A., Schrack, J., Ying, H., Olorundare, I., Warsame, F., Mountford, A., Haugen, C. E., González Fernández, M., Norman, S. P., Segev, D. L. 2017


    Prediction models for post-kidney transplantation mortality have had limited success (C-statistics ≤0.70). Adding objective measures of potentially modifiable factors may improve prediction and, consequently, kidney transplant (KT) survival through intervention. The Short Physical Performance Battery (SPPB) is an easily administered objective test of lower extremity function consisting of three parts (balance, walking speed, chair stands), each with scores of 0-4, for a composite score of 0-12, with higher scores indicating better function. SPPB performance and frailty (Fried frailty phenotype) were assessed at admission for KT in a prospective cohort of 719 KT recipients at Johns Hopkins Hospital (8/2009 to 6/2016) and University of Michigan (2/2013 to 12/2016). The independent associations between SPPB impairment (SPPB composite score ≤10) and composite score with post-KT mortality were tested using adjusted competing risks models treating graft failure as a competing risk. The 5-year posttransplantation mortality for impaired recipients was 20.6% compared to 4.5% for unimpaired recipients (p < 0.001). Impaired recipients had a 2.30-fold (adjusted hazard ratio [aHR] 2.30, 95% confidence interval [CI] 1.12-4.74, p = 0.02) increased risk of postkidney transplantation mortality compared to unimpaired recipients. Each one-point decrease in SPPB score was independently associated with a 1.19-fold (95% CI 1.09-1.30, p < 0.001) higher risk of post-KT mortality. SPPB-derived lower extremity function is a potentially highly useful and modifiable objective measure for pre-KT risk prediction.

    View details for DOI 10.1111/ajt.14430

    View details for PubMedID 28710900

  • Characterizing the relationship between age and venous thromboembolism in adult trauma patients: findings from the National Trauma Data Bank and the National Inpatient Sample. The Journal of surgical research Nastasi, A. J., Canner, J. K., Lau, B. D., Streiff, M. B., Aboagye, J. K., Kraus, P. S., Hobson, D. B., Van Arendonk, K. J., Haut, E. R. 2017; 216: 115–22


    Venous thromboembolism (VTE) is a tremendous burden in health care. However, current guidelines lack recommendations regarding the prevention of VTE in older adult trauma patients. Furthermore, the appropriate method of modeling of age in VTE models is currently unclear.Patients included in the National Trauma Data Bank (NTDB) between the years 2008 and 2014 and patients included in the National Inpatient Sample (NIS) between 2009 and 2013 were analyzed. Multiple logistic regression of VTE on age was performed.Of 3,598,881 patients in the NTDB, 34,202 (1.0%) were diagnosed with VTE compared to 5405 (1.1%) of the 505,231 patients in NIS. In both the fully adjusted NTDB and NIS model, age was positively associated with odds of VTE diagnosis under 65 years (NTDB, adjusted odds ratio [aOR]: 1.018, 95% confidence interval [CI]: 1.017-1.019, P < 0.001; NIS, aOR: 1.025, 95% CI 1.022-1.027, P < 0.001). In patients aged ≥65 years, age was negatively associated with odds of VTE diagnosis in the NTDB (aOR: 0.995, 95% CI: 0.992-0.999, P = 0.006) but not in the NIS (aOR: 0.998, 95% CI 0.994-1.002, P = 0.26).Incidence of VTE among adult trauma patients steadily increases with age until 65 years, after which the odds of VTE appear to level off or even slightly decrease. These findings should be applied for improved modeling of VTE in trauma patients. The mechanism behind these findings should be explored before using them to update guidelines for standardized VTE prevention in older adults.

    View details for DOI 10.1016/j.jss.2017.04.033

    View details for PubMedID 28807195

  • Objectively Measured Physical Activity and Falls in Well-Functioning Older Adults: Findings From the Baltimore Longitudinal Study of Aging. American journal of physical medicine & rehabilitation Nastasi, A. J., Ahuja, A., Zipunnikov, V., Simonsick, E. M., Ferrucci, L., Schrack, J. A. 2017


    Previous work demonstrates the consequences of falling in older adults and the potential of physical activity (PA) to reduce falls, but few studies have used accelerometer-measured PA to compare overall and time-of-day activity patterns of nonfallers, fallers, or subgroups of fallers.In 840 participants (mean age, 66.7; s = 13.2; range, 26-97) of the Baltimore Longitudinal Study of Aging between 2007 and 2014, PA was measured objectively with Actiheart accelerometers and falling status (faller/nonfaller) was assessed during an in-person interview. Differences in daily PA and PA by time-of-day were assessed using multiple linear regression. Differences in PA (multiple linear regression), and functional status (χ) were further examined in subgroups of "risky" or "normal" fallers.Overall, fallers and nonfallers exhibited similar daily (β = 22.6, P = 0.48) and time-specific PA; however, those who fell doing risky activities were more active overall (β = 243.8, P = 0.002), during the morning (β = 77.3, P = 0.004), afternoon (β = 78.4, P = 0.001), and late afternoon/evening (β = 56.3, P = 0.006) than those who fell doing normal activities. Risky fallers were significantly higher functioning than normal fallers.Persons who fell while engaging in normal activities exhibited lower PA overall and throughout most of the day, and were of lower functional status than persons who fell while engaging in risky or unusual activities, suggesting that engagement in risky or unusual PA is associated with higher functional ability and lower falls risk in older persons.

    View details for DOI 10.1097/PHM.0000000000000830

    View details for PubMedID 28915202

Latest information on COVID-19