Influenza vaccination patterns among at-risk patients during the Covid-19 pandemic-a retrospective cross-sectional study based on claims data.

PURPOSE: The Covid-19 pandemic may have encouraged at-risk patients to get vaccinated against influenza for the first time. As previous vaccinations are known predictors for further vaccinations, knowledge about individual vaccination patterns, especially in first time vaccinated patients, is of great interest. The aim of this study was to determine influenza vaccination uptake rate (VUR), individual vaccination patterns and factors associated with vaccination uptake among at-risk patients. METHODS: The study design was retrospective cross-sectional. Based on claims data, VUR was determined for four influenza seasons (2018/2019-2021/2022). In a cohort subgroup, with data available for all seasons, VUR, vaccination patterns and factors associated with uptake were determined. At-risk patients were people aged ≥ 65 and adult patients with chronic diseases. RESULTS: We included n = 238,461 patients in the cross-sectional analysis. Overall VUR ranged between 21.8% (2018/2019) and 29.1% (2020/2021). Cohort subgroup consisted of n = 138,526 patients. Within the cohort, 56% were never vaccinated and 11% were vaccinated in all seasons. 14.3% of previously unvaccinated patients were vaccinated for the first time in the first pandemic season (2020/2021 season). The strongest predictor for vaccination was history of vaccinations in all previous seasons (OR 56.20, 95%CI 53.62-58.90, p < 0.001). CONCLUSION: Influenza VUR increased during the Covid-19 pandemic, but only a minority of previously eligible but unvaccinated at-risk patients were vaccinated for the first time in the first pandemic season. Previous vaccinations are predictors for subsequent vaccinations and health care professionals should actively address at-risk patients' vaccination history in order to recommend vaccination in future seasons.

Influenza vaccination uptake among at-risk patients in Switzerland-The potential of national claims data for surveillance.

Background: Swiss national surveillance of influenza vaccination uptake rates (VURs) relies on self-reported vaccination status. The aim of this study was to determine VURs among at-risk patients, namely, patients ≥65 of age and adult patients with chronic diseases, using claims data, instead of self-reported measures, to investigate factors of vaccine uptake, and to assess different methodological approaches to conduct vaccination surveillance. Methods: In this retrospective cross-sectional analysis, we determined VURs in three influenza seasons (2015/2016-2017/2018). Medication, diagnosis, or medical services claims were used as triggers to identify patients. For the calculation of VURs in patients with chronic diseases, we identified those by triggers in the given season only (Model 1) and in the given and previous seasons (Model 2). Regression analysis was used to identify factors associated with vaccination status. Results: Data from 214,668 individual patients were analyzed. VURs over all seasons ranged from 18.4% to 19.8%. Most patients with chronic diseases were identified with the medication trigger, and we found no clinical significant differences in VURs comparing both models. Having a chronic disease, age, male gender, and regular health care provider visits were associated with increased odds of being vaccinated. Conclusions: VURs were below the recommended thresholds, and our analysis highlighted the need for efforts to increase VURs. We assessed the identification of chronic diseases by medication claims and the calculation of VURs based on data of the given season only as an effective approach to conduct vaccination surveillance. Claims data-based surveillance may complete the national surveillance.

Exploring Patient Multimorbidity and Complexity Using Health Insurance Claims Data: A Cluster Analysis Approach.

BACKGROUND: Although the trend of progressing morbidity is widely recognized, there are numerous challenges when studying multimorbidity and patient complexity. For multimorbid or complex patients, prone to fragmented care and high health care use, novel estimation approaches need to be developed. OBJECTIVE: This study aims to investigate the patient multimorbidity and complexity of Swiss residents aged ≥50 years using clustering methodology in claims data. METHODS: We adopted a clustering methodology based on random forests and used 34 pharmacy-based cost groups as the only input feature for the procedure. To detect clusters, we applied hierarchical density-based spatial clustering of applications with noise. The reasonable hyperparameters were chosen based on various metrics embedded in the algorithms (out-of-bag misclassification error, normalized stress, and cluster persistence) and the clinical relevance of the obtained clusters. RESULTS: Based on cluster analysis output for 18,732 individuals, we identified an outlier group and 7 clusters: individuals without diseases, patients with only hypertension-related diseases, patients with only mental diseases, complex high-cost high-need patients, slightly complex patients with inexpensive low-severity pharmacy-based cost groups, patients with 1 costly disease, and older high-risk patients. CONCLUSIONS: Our study demonstrated that cluster analysis based on pharmacy-based cost group information from claims-based data is feasible and highlights clinically relevant clusters. Such an approach allows expanding the understanding of multimorbidity beyond simple disease counts and can identify the population profiles with increased health care use and costs. This study may foster the development of integrated and coordinated care, which is high on the agenda in policy making, care planning, and delivery.

Continuity of care and multimorbidity in the 50+ Swiss population: An analysis of claims data.

Objective: To assess the relationship between continuity of care (COC) and multimorbidity in the older general population in Switzerland, accounting for relevant determinants of COC, and to apply various expressions of multimorbidity derived from claims data. Methods: We used data on 240'000 insured individuals aged 50+ for the period 2015-2018, received from one of the largest Swiss health insurance company. We calculated Bice-Boxerman index based on all doctor visits (overall COC) and visits to the general practitioners (COC GP). We analyzed the relationship between COC and multimorbidity using generalized linear and probit models. To express multimorbidity, we applied three approaches based on pharmacy-cost groups (PCGs) assigned to an individual. First, we used simple PCG counts. Second, we expressed multimorbidity via clinically relevant disease groups derived from PCGs. Finally, a data-driven approach allowed defining distinct clusters representing different patient complexities. Results: The association between overall COC and multimorbidity expressed in PCG counts was modest: COC among individuals with 3+ PCGs was 2 percentage points higher than COC among individuals with 0 PCGs. The approach of clinically relevant disease groups showed larger variation in COC and its association with multimorbidity. The data-driven approach showed that most complex ("high-cost high-need") individuals tended to have higher overall COC. Additionally, 70% of the sample visited exclusively one general practitioner (COC GP = 1.0). Other important factors associated with COC in the Swiss context were insurance model with gatekeeping, level of deductibles, and region of residence. Conclusions: Multimorbid patients require regular medical attention often involving multiple healthcare providers, which can lead to varying COC, depending on types of doctors seen and specific condition of the patient. Insurance models with gatekeeping may facilitate COC, prompting developments of better-designed models of care. This represents important implications for policymakers, health insurance representatives, medical professionals and hospital managers.

Characteristics and health care costs in patients with a diagnostic imaging for low back pain in Switzerland.

Low back pain (LBP) is one of the most common musculoskeletal disorders worldwide and a frequent cause for health care utilization with a high economic burden. A large proportion of diagnostic imaging in patients with LBP is inappropriate and can cause more harm than good, which in turn can lead to higher health care costs. The aim of this study was to determine characteristics and health care costs for patients with a diagnostic imaging for LBP in Switzerland. Groupe Mutuel, one of the biggest health care insurance companies in Switzerland and covering approximately 12% of the population, provided data for this analysis. Patients were identified by diagnostic imaging for the lumbar spine in 2016 or 2017. The study period was 2015-2019, that is one year before and two years after the year of imaging. Regression analysis models were used to identify patient variables associated with higher health care costs. A total of 75,296 patients (57% female, mean age: 54.5 years) were included into the study. Magnetic resonance imaging was the most commonly used diagnostic method (44.3%). Patients generated annual mean health care costs of 518,488,470 CHF (466,639,621 Euro) in the whole observation period; 640 million CHF (576 million Euro) in the index year. Overall, costs for LBP patients were 72% higher compared with the costs of no LBP patients. Our findings confirm the economic burden of LBP and highlight the importance of ongoing efforts to improve prevention, diagnostics and patient care in patients with LBP.

Continuity of care of Swiss residents aged 50+: a longitudinal study using claims data.

Background: Continuity of care (COC) should be measured for healthcare quality monitoring and evaluation and is a key process indicator for integrated care. Measurement of COC using routinely collected data is widespread, but there is no consensus on which indicator to use and the relevant time horizon to apply. Information about COC is especially warranted in highly fragmented healthcare systems, such as in Switzerland. Our study aimed to compare COC measures in Swiss residents aged 50+ obtained with various indices and time horizons. Methods: Using insurance claims data, we computed and compared several commonly used visit-based Continuity of Care Indices (COCIs): Bice-Boxerman Index, Usual Provider of Care, Herfindahl-Hirschman Index, Modified, Modified Continuity Index and Modified Continuity Index, based on all doctor visits and on primary care (PC) visits only. Indices were computed over short (1 year) and medium (4 years) terms. Results: The mean indices based on all visits varied between 0.51 and 0.77, while PC indices presented less variation with a median of 1.00 for all but one index. Indices focusing on a variety of individual providers decreased with time horizon, while indices focusing on the overall number of visits and providers showed the opposite trend. These findings suggest fundamental differences in the interpretation of COCIs. Conclusions: Broad COC appeared moderately low in Switzerland, although comparable to other countries, and PC COC was close to one. The choice of indices and time horizon influenced their interpretation. Understanding these differences is key to select the appropriate index for the monitoring of COC.

Treatment Patterns in Patients with Diagnostic Imaging for Low Back Pain: A Retrospective Observational Study.

PURPOSE: Low back pain (LBP) is one of the most frequent reasons for medical consultations. Literature suggests a large evidence-performance gap, especially regarding pain management. Therefore, the monitoring of treatment patterns is important to ensure high quality of treatment. This study aimed to describe treatment patterns specific to patients with diagnostic imaging of the spine for LBP. PATIENTS AND METHODS: The study was retrospective observational and based on health claims data from 2015 to 2019 provided by a Swiss health insurance company covering around 12% of the population. Patients, ≥18 years of age, with diagnostic imaging of the spine were included and observed 12 months before and after imaging. Patients with back surgery or comorbidities associated with the use of pain medications were excluded. RESULTS: In total, 60,822 patients (mean age: 53.5 y, 56.1% female) were included and 85% received at least one pain medication. Of these, non-steroidal anti-inflammatory drugs, paracetamol, or opioids were prescribed in 88.6%, 70.7%, and 40.3% of patients, respectively. Strong opioids were used in 17% of patients given opioids. Patients with combinations of diagnostic imaging methods had the highest odds of receiving pain medication prescriptions (1.81, 95% CI: 1.66, 1.96, P < 0.001). Prescribed defined daily doses corresponded to short-term therapies. CONCLUSION: Although the majority of patients received non-opioid short-term therapies, we found a substantial use of opioids, and in particular, a relative high usage of strong opioids. Our results highlighted the importance of both patient and healthcare provider awareness regarding the prudent treatment of LBP.

Patterns of benzodiazepine prescription among older adults in Switzerland: a cross-sectional analysis of claims data.

OBJECTIVE: This study aimed to examine the prevalence and determinants of benzodiazepine prescription among older adults in Switzerland, and analyse association with hospitalisation and costs. DESIGN: Retrospective analysis of claims data. SETTING: The study was conducted in nine cantons in Switzerland. PARTICIPANTS: Older adults aged 65 years and older enrolled with a large Swiss health insurance company participated in the study. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary outcome was prevalence of benzodiazepine prescription. The secondary outcomes were (1) determinants of any benzodiazepine prescription; (2) the association between any prescription and the probability of hospitalisation for trauma and (3) the association between any prescription and total healthcare expenditures. RESULTS: Overall, 69 005 individuals were included in the study. Approximately 20% of participants had at least one benzodiazepine prescription in 2017. Prescription prevalence increased with age (65-69: 15.9%; 70-74: 18.4%; 75-80: 22.5%; >80: 25.8%) and was higher in women (25.1%) compared with men (14.6%). Enrollees with the highest deductible of Swiss Francs (CHF) 2500 were 70% less likely to receive a prescription than enrollees with the lowest deductible of CHF 300 (adjusted OR=0.29, 95% CI 0.24 to 0.35).Individuals with at least one prescription had a higher probability of hospitalisation for trauma (OR=1.31, 95% CI 1. 20 to 1.1.44), and 70% higher health care expenditures (ß=0.72, 95% CI 0. 67 to 0.77). Enrollees in canton Valais were three times more likely to receive a prescription compared to enrollees from canton Aargau (OR=2.84, 95% 2.51 to 3.21). CONCLUSIONS: The proportion of older adults with at least one benzodiazepine prescription is high, as found in the data of one large Swiss health insurance company. These enrollees are more likely to be hospitalised for trauma and have higher healthcare expenditures. Important differences in prescription prevalence across cantons were observed, suggesting potential overuse. Further research is needed to understand the drivers of variation, prescription patterns across providers, and trends over time.