A population-centered model for public health medicine.

OBJECTIVES: Public health physicians (PHPs) are trained in both medicine and public health, yet practice models in each of these fields incompletely describe their work. A model of practice for public health physicians would better enable training and professional development in the specialty. The objective of this study was to develop an empirically grounded method of the practice of public health medicine by public health physicians. STUDY DESIGN: This was designed as a constructivist grounded theory (CGT) study. Semistructured interviews with 18 public health physicians in Canada were conducted over the course of 1 year. METHODS: Transcribed interviews were coded in three stages (line-by-line, focused, and theoretical). Constant comparison, theoretical sampling, reflective and analytic memos, and team discussion on reflexivity were used to ensure rigor and the proper application of CGT methods. RESULTS: The key finding of this study is the population-centered medical method (POP-CMM), an empirically grounded method of PHP practice. In this model, PHPs bring values, knowledge, and stances to their practice of medicine with populations as patients. They work to diagnose and intervene on public health issues, with a focus on prevention and systems. Essential to this work is knowledge sharing and relationship building between physicians and populations. CONCLUSIONS: POP-CMM represents a method of practice for PHPs. Further exploration of this method in other countries and systems would bring insight into PHP practice globally. The model has important connections to the practice of medicine and presents the possibility of developing a general model of physician practice for a range of patients, from individuals to populations.

Under-mask beard covers achieve an adequate seal with tight-fitting disposable respirators using quantitative fit testing.

BACKGROUND: Tight-fitting respirators are a critical component of respiratory protection against airborne diseases for health workers. However, they are not recommended for health workers with facial hair. Some health workers are unable to shave for religious or medical reasons. Under-mask beard covers have been proposed as a solution to allow health workers with facial hair to wear tight-fitting respirators. However, studies to date have been limited by their predominant reliance on qualitative rather than quantitative fit testing techniques. AIM: To assess the efficacy of under-mask beard covers in achieving an adequate seal with tight-fitting disposable P2/N95 respirators using quantitative fit testing. METHODS: Bearded adult males underwent quantitative fit testing with an under-mask beard cover using either a TSI PortaCount Respirator Fit Tester 8038 or an AccuFit 9000 PRO fit testing device on up to five disposable P2/N95 respirators (3M 1860, 3M 1870+, BYD N95 Healthcare Particulate Respirator, BSN Medical ProShield N-95 Medium and Trident RTCFFP2). The primary outcome was the proportion of subjects that passed or failed quantitative fit testing with an under-mask beard cover. FINDINGS: Thirty subjects were assessed; of these, 24 (80%) passed quantitative fit testing with at least one tight-fitting P2/N95 disposable respirator. Among these subjects, the median best-achieved fit factor was 200 (interquartile range 178-200). None of the subjects had an adverse reaction to the under-mask beard cover. CONCLUSION: The under-mask beard cover technique may be used to achieve a satisfactory seal with tight-fitting P2/N95 respirators in health workers with facial hair who cannot shave.

Surgical margins for borderline and malignant phyllodes tumours.

BACKGROUND: Phyllodes tumours represent less than 1% of all UK breast neoplasms. Histological features allow classification into benign, borderline or malignant, which has a significant impact on prognosis and recurrence. Currently, there is no consensus for the optimal surgical excision margin. This systematic review aims to provide a comparative summary of outcomes (local recurrence, metastasis and survival) for borderline and malignant phyllodes tumours resected with either ≥1cm or <1cm margins. METHODS: MEDLINE and Embase were systematically searched (1990 to July 2019), in line with PRISMA guidelines. Study quality was assessed using the Newcastle-Ottawa scale. RESULTS: Ten retrospective studies were included (Newcastle-Ottawa scale mean score: 5.6, range: 8-4). Nine reported local recurrence rates, four reported distant metastasis and four reported survival. Meta-analysis pooling demonstrated no statistically significant difference between <1cm and ≥1cm margins in terms of local recurrence rates (relative risk [RR] 1.43, 95% confidence interval [95% CI] 0.70 - 2.93; p=0.33, n=456), distant metastasis (RR 1.93, 95% CI 0.35 - 10.63; p=0.45, n=72) or mortality (RR 1.93, 95% CI 0.42 - 8.77; p=0.40, n=58) for borderline and malignant tumours. Additionally, two studies demonstrated no significant difference in local recurrence for borderline tumours excised with <0.1cm margins compared to ≥1cm. CONCLUSION: Current evidence suggests that margins <1cm may provide adequate tumour excision. This could enable breast conservation in patients with smaller breast-to-tumour volume ratios, with improved cosmetic outcomes and patient satisfaction. A prospective, multi-institutional trial would be appropriate to further elucidate the safety of smaller margins.

Concordance between health administrative data and survey-derived diagnoses for mood and anxiety disorders.

OBJECTIVE: To assess whether estimates of survey structured interview diagnoses of mood and anxiety disorders were concordant with diagnoses of these disorders obtained from health administrative data. METHODS: All Ontario respondents to the 2012 Canadian Community Health Survey-Mental Health (CCHS-MH) were linked to health administrative databases at ICES (formerly known as the Institute for Clinical Evaluative Sciences). Survey structured interview diagnoses were compared with health administrative data diagnoses obtained using a standardized algorithm. We used modified Poisson regression analyses to assess whether socio-demographic factors were associated with concordance between the two measures. RESULTS: Of the 4157 Ontarians included in our sample, 20.4% had either a structured interview diagnosis (13.9%) or health administrative diagnosis (10.4%) of a mood or anxiety disorder. There was high discordance between measures, with only 19.4% agreement. Migrant status, age, employment, and income were associated with discordance between measures. CONCLUSIONS: Our findings indicate that previous estimates of the 12-month prevalence of mood and anxiety disorders in Ontario may be underestimating the true prevalence, and that population-based surveys and health administrative data may be capturing different groups of people. Understanding the limitations of data commonly used in epidemiologic studies is a key foundation for improving population-based estimates of mental disorders.

Inequitable health service use in a Canadian paediatric population: A cross-sectional study of individual- and contextual-level factors.

BACKGROUND: Health service use may be influenced by multilevel predisposing, enabling, and need factors but is equitable when driven by need. The study's objectives were as follows: (a) to investigate residential context's effect on child health service use and (b) to examine inequity of child health service use by testing for effect measure modification of need factors. METHODS: The sample of 1,451 children was from a prenatal cohort recruited from London, Ontario, between 2002 and 2004, with follow-up until children were toddler/preschooler-aged. Individual-level data were linked by residential address to neighbourhood contextual-level data sourced from Statistics Canada. Multilevel logistic regression modelled factors associated with child health service use. Interaction terms were included in the model to test for effect measure modification of need factors by predisposing and enabling factors. RESULTS: Contextual-level factors were not associated with child health service use. Maternal parity and nativity to Canada modified the effect of the need factor, paediatric health condition, on health service use. Health condition's effect was lowest in children of Canadian-born mothers with one child only (OR = 1.58, p = .04) and highest in children of Canadian-born mothers with three or more children (OR = 3.52, p < .01). Further, its effect was higher in children of Canadian-born mothers compared to children of mothers who migrated to Canada; however, odds ratios were not statistically significant for the latter. CONCLUSIONS: Results may inform future investigation of the potential inequity of health service use for subgroups of children whose mothers are of lower parity and not Canadian-born. An understanding of these inequities may inform future healthcare policy and care for paediatric populations.

Costs of cervical cancer treatment: population-based estimates from Ontario.

OBJECTIVES: The objectives of the present study were to estimate the overall and specific medical care costs associated with cervical cancer in the first 5 years after diagnosis in Ontario. METHODS: Incident cases of invasive cervical cancer during 2007-2010 were identified from the Ontario Cancer Registry and linked to administrative databases held at the Institute for Clinical Evaluative Sciences. Mean costs in 2010 Canadian dollars were estimated using the arithmetic mean and estimators that adjust for censored data. RESULTS: Mean age of the patients in the study cohort (779 cases) was 49.3 years. The mean overall medical care cost was $39,187 [standard error (se): $1,327] in the 1st year after diagnosis. Costs in year 1 ranged from $34,648 (se: $1,275) for those who survived at least 1 year to $69,142 (se: $4,818) for those who died from cervical cancer within 1 year. At 5 years after diagnosis, the mean overall unadjusted cost was $63,131 (se: $3,131), and the cost adjusted for censoring was $68,745 (se: $2,963). Inpatient hospitalizations and cancer-related care were the two largest components of cancer treatment costs. CONCLUSIONS: We found that the estimated mean costs that did not account for censoring were consistently undervalued, highlighting the importance of estimates based on censoring-adjusted costs in cervical cancer. Our results are reliable for estimating the economic burden of cervical cancer and the cost-effectiveness of cervical cancer prevention strategies.

Secular trends in the survival of patients with laryngeal carcinoma, 1995-2007.

BACKGROUND: Recent reports suggest a decline over time in the survival of patients newly diagnosed with laryngeal cancer in spite of developments in treatment practices. Our study set out to determine whether the survival of patients with laryngeal cancer in Ontario has changed over time. METHODS: This population-based cohort study of patients diagnosed with laryngeal cancer in the province of Ontario between 1995 and 2007 used data extracted from linked provincial administrative and registry databases. Its main outcomes were overall survival, laryngectomy-free survival, and survival ratio relative to an age- and sex-matched general population. RESULTS: The 4298 patients newly diagnosed with laryngeal cancer during the period of interest were predominantly men (n = 3615, 84.1%) with glottic cancer (n = 2787, 64.8%); mean age in the group was 66 years (interquartile range: 59-74 years). Patient demographics did not significantly change over time. Overall, 5-year survival was 57.4%; laryngectomy-free survival was 45.4%. Comparing patients from three eras (1995-1998, 1999-2003, 2004-2007) and adjusting for age, sex, and comorbidity status, we observed no differences in overall survival or laryngectomy-free survival over time. The 5-year relative survival ratio for patients with laryngeal cancer compared with an age- and sex-matched group from the general population was 81.1% for glottic cancer and 44.5% for supraglottic cancer. CONCLUSIONS: In patients with a new diagnosis of laryngeal cancer, overall and laryngectomy-free survival have remained unchanged since the mid-1990s. New methods to improve survival and the rate of laryngeal preservation in this patient population are needed.

In vitro effects of propofol on gravid human myometrium.

The aim of this study was to evaluate the direct effect of propofol (di-isopropyl phenol) on the contractile properties of gravid human uterine muscle. Six specimens of uterine muscle were obtained from term parturients undergoing elective lower segment caesarean section. Small strips (1 x 2 x 12 mm) of muscle were prepared and suspended in an organ bath containing oxygenated Kreb's solution at 36.5 degrees C. Following preparation, spontaneous regular contractions developed at a rate of one contraction every six to 10 minutes. Force of contraction was recorded continuously using an isometric tension transducer Following baseline measurements, propofol was introduced into the bath at concentrations corresponding to 2 microg/ml, 5 mcirog/ml and 8 mirog/ml. The specimens were also exposed to intralipid in concentrations equivalent to that found in the 8 microg/ml solution of propofol to determine whether this additive influenced uterine contractility. Contractility (defined as area under the tension/time curve) was decreased to 89 +/- 6.5% of control at 2 microg/ml, 53 +/- 4.3% at 5 microg/ml and 45 +/- 4.1% at 8 microg/ml. This decrease in contractility was statistically significant at concentrations >2 microg/ml. Intralipid did not significantly affect uterine contractility. The results of this study show that propofol decreases isolated human uterine muscle contractility in a dose-dependent manner

Cost-efficient radical prostatectomy with a clinical care path.

PURPOSE: We assessed changes in hospital costs and resource use among patients undergoing radical prostatectomy following implementation of a clinical care path. MATERIALS AND METHODS: A standardized clinical care path for patient management before and after radical prostatectomy was developed and implemented at a large academic medical center in California. All 577 consecutive patients undergoing radical prostatectomy during the 3 years before and 1 year after implementation of the care path were included in the study. Each patient was entered prospectively into a hospital-wide financial data base, which served as the source for observations on hospital costs, hospital charges and length of stay. RESULTS: After implementation of the radical prostatectomy care path hospital costs decreased by 12% ($7,916 versus $6,934, p < 0.001), hospital charges decreased by 20% ($17,005 versus $13,524, p < 0.0001) and length of stay decreased by 28% (5 versus 3.6 days, p < 0.0001). Decreases were noted in all categories of the hospital patient financial profile, except operating room charges. CONCLUSIONS: By standardizing preoperative and postoperative management for patients undergoing radical prostatectomy, significant savings can be achieved over and above existing trends toward shorter hospital stays and lower hospital costs.

Platelets and leukocytes in the lungs after acute hypobaric hypoxia.

To determine if decompression from sea level causes aggregation and embolization of platelets or leukocytes to the lungs, we have measured the accumulation of 51Cr-labeled platelets or 111In-labeled leukocytes in the lungs of rabbits decompressed to 440 or 350 Torr for 18 or 40 h. To be certain that any increased accumulation of labeled platelets (or leukocytes) in the lungs was not just caused by an increased pulmonary blood volume we also labeled the rabbits red blood cells with 59Fe. There was no detectable accumulation of labeled platelets in the lungs on decompression. In control animals there were 22 times as many labeled leukocytes in the lungs as could be accounted for by the volume of blood in the lungs. In experimental animals at 326 Torr for 18 h this figure was reduced to 13.6. Hypobaric hypoxia caused an increase in circulating granulocytes from a mean of 3.3 +/- 1.6 X 10(9)/l to 5.3 +/- 2.1 X 10(9)/l. (P less than 0.005). Our results suggest that decompressions to 6,100 m for 18 h does not cause platelet sequestration in the lungs but does cause a significant reduction in leukocytes in the lungs and a peripheral granulocytosis.