Estimating the incidence of breast cancer recurrence using administrative data.

BACKGROUND: Breast cancer is the most common cancer among women, but most cancer registries do not capture recurrences. We estimated the incidence of local, regional, and distant recurrences using administrative data. METHODS: Patients diagnosed with stage I-III primary breast cancer in Ontario, Canada from 2013 to 2017 were included. Patients were followed until 31/Dec/2021, death, or a new primary cancer diagnosis. We used hospital administrative data (diagnostic and intervention codes) to identify local recurrence, regional recurrence, and distant metastasis after primary diagnosis. We used logistic regression to explore factors associated with developing a distant metastasis. RESULTS: With a median follow-up 67 months, 5,431/45,857 (11.8%) of patients developed a distant metastasis a median 23 (9, 42) months after diagnosis of the primary tumor. 1086 (2.4%) and 1069 (2.3%) patients developed an isolated regional or a local recurrence, respectively. Patients with distant metastatic disease had a median overall survival of 15.4 months (95% CI 14.4-16.4 months) from the time recurrence/metastasis was identified. In contrast, the median survival for all other patients was not reached. Patients were more likely to develop a distant metastasis if they had more advanced stage, greater comorbidity, and presented with symptoms (p < 0.0001). Trastuzumab halved the risk of recurrence [OR 0.53 (0.45-0.63), p < 0.0001]. CONCLUSION: Distant metastasis is not a rare outcome for patients diagnosed with breast cancer, translating to an annual incidence of 2132 new cases (17.8% of all breast cancer diagnoses). Overall survival remains high for patients with locoregional recurrences, but was poor following a diagnosis of a distant metastasis.

Differences in breast cancer diagnosis by patient presentation in Ontario: a retrospective cohort study.

BACKGROUND: In Ontario, patients with breast cancer typically receive their diagnoses through the Ontario Breast Screening Program (OBSP) after an abnormal screen, through screening initiated by a primary care provider or other referring physician, or through follow-up of symptoms by patients' primary care providers. We sought to explore the association of the route to diagnosis (screening within or outside the OBSP or via symptomatic presentation) with use of OBSP-affiliated breast assessment sites (O-BAS), wait times until diagnosis or treatment, health care use and overall survival for patients with breast cancer. METHODS: In this retrospective cohort study, we used the Ontario Cancer Registry to identify adults (aged 18-105 yr) who received a diagnosis of breast cancer from 2013 to 2017. We excluded patients if they were not Ontario residents or had missing age or sex, or who died before diagnosis. We used logistic regression to evaluate factors associated with categorical variables (whether patients were or were not referred to an OBAS, whether patients were screened or symptomatic) and Cox proportional hazards regression to identify factors associated with all-cause mortality. RESULTS: Of 51 460 patients with breast cancer, 42 598 (83%) received their diagnoses at an O-BAS. Patients whose cancer was first detected through the OBSP were more likely than symptomatic patients to be given a diagnosis at an O-BAS (adjusted odds ratio 1.68, 95% confidence interval [CI] 1.57 to 1.80). Patients screened by the OBSP were given their diagnoses 1 month earlier than symptomatic patients, but diagnosis at an O-BAS did not affect the time until either diagnosis or treatment. Patients referred to an O-BAS had significantly better overall survival than those who were not referred (adjusted hazard ratio 0.73, 95% CI 0.66 to 0.80). INTERPRETATION: Patients screened through the OBSP were given their diagnoses earlier than symptomatic patients and were more likely to be referred to an O-BAS, which was associated with better survival. Our findings suggest that individuals with signs and symptoms of breast cancer would benefit from similar referral processes, oversight and standards to those used by the OBSP.

Mortality, Health Care Use, and Costs of Weaning Center Survivors and Matched Prolonged ICU Stay Controls.

BACKGROUND: Quantification of long-term survival, health care utilization, and costs of prolonged ventilator dependence informs patient/family decision-making, health care policy, and understanding of specialized weaning centers (SWCs) as alternate care models. Our objective was to compare survival trajectory, health care utilization, and costs of SWC survivors with a matched cohort of ≥ 21-d-stay ICU patients. METHODS: This was a retrospective longitudinal (12 y) case-control study linking to health administrative databases with matching on age, sex, Charlson comorbidity index, income quintiles, and days in ICU and hospital in preceding 12 months. RESULTS: We matched 201 SWC subjects to 201 prolonged ICU survivors (402-subject cohort); 42% had a Charlson score of > 4. Risk of death at 12 months was lower in SWC subjects (hazard ratio [HR] 0.70 [95% CI 0.54-0.91]) adjusting for length of hospital admission (HR 1.02 [95% CI 1.00-1.04]) and number of care location transfers (HR 0.84 [95% CI 0.75-0.93]). By follow-up end, more SWC subjects died, 149 (73%) versus 127 (62%). We found no difference in discharge to home. At 12 months, acute health care utilization was comparable for the entire cohort, except hospital readmission rates (median interquartile range [IQR] 2 [1-3) vs 1 [1-2] d). Median (IQR) cost 12 months after unit discharge was CAD $68,165 ($19,894-$153,475). 12-month costs were higher in the SWC survivors (CAD $82,874 [$29,942-$224,965] vs CAD $55,574 [$6,572-$128,962], P < .001). SWC survivors had higher community health care utilization. Regression modeling demonstrated cost was associated with stay and care transfers but not SWC admission. Over 12-y follow-up, health care utilization and costs were higher in SWC survivors. CONCLUSIONS: SWC admission may confer some medium-term survival advantage; however, this may be influenced by selection bias associated with admission criteria.

Principal component analysis of socioeconomic factors and their association with malaria and arbovirus risk in Tanzania: a sensitivity analysis.

Principal component analysis (PCA) is frequently adopted for creating socioeconomic proxies in order to investigate the independent effects of wealth on disease status. The guidelines and methods for the creation of these proxies are well described and validated. The Demographic and Health Survey, World Health Survey and the Living Standards Measurement Survey are examples of large data sets that use PCA to create wealth indices particularly in low and middle-income countries (LMIC), where quantifying wealth-disease associations is problematic due to the unavailability of reliable income and expenditure data. However, the application of this method to smaller survey data sets, especially in rural LMIC settings, is less rigorously studied.In this paper, we aimed to highlight some of these issues by investigating the association of derived wealth indices using PCA on risk of vector-borne disease infection in Tanzania focusing on malaria and key arboviruses (ie, dengue and chikungunya). We demonstrated that indices consisting of subsets of socioeconomic indicators provided the least methodologically flawed representations of household wealth compared with an index that combined all socioeconomic variables. These results suggest that the choice of the socioeconomic indicators included in a wealth proxy can influence the relative position of households in the overall wealth hierarchy, and subsequently the strength of disease associations. This can, therefore, influence future resource planning activities and should be considered among investigators who use a PCA-derived wealth index based on community-level survey data to influence programme or policy decisions in rural LMIC settings.