Enabling analytics on sensitive medical data with secure multi-party computation

While there is a clear need to apply data analytics in the healthcare sector, this is often difficult because it requires combining sensitive data from multiple data sources. In this paper, we show how the cryptographic technique of secure multiparty computation can enable such data analytics by performing analytics without the need to share the underlying data. We discuss the issue of compliance to European privacy legislation; report on three pilots bringing these techniques closer to practice; and discuss the main challenges ahead to make fully privacy-preserving data analytics in the medical sector commonplace

Does Centralization of Radical Prostatectomy Reduce the Incidence of Postoperative Urinary Incontinence?

Background: On the basis of previous analyses of the incidence of urinary incontinence (UI) after radical prostatectomy (RP), the hospital RP volume threshold in the Netherlands was gradually increased from 20 per year in 2017, to 50 in 2018 and 100 from 2019 onwards. Objective: To evaluate the impact of hospital RP volumes on the incidence and risk of UI after RP (RP-UI). Design, setting, and participants: Patients who underwent RP during 2016–2020 were identified in the claims database of the largest health insurance company in the Netherlands. Incontinence was defined as an insurance claim for ≥1 pads/d. Outcome measurements and statistical analysis: The relationship between hospital RP volume (HV) and RP-UI was assessed via multivariable analysis adjusted for age, comorbidity, postoperative radiotherapy, and lymph node dissection. Results and limitations: RP-UI incidence nationwide and by RP volume category did not decrease significantly during the study period, and 5-yr RP-UI rates varied greatly among hospitals (19–85%). However, low-volume hospitals (≤120 RPs/yr) had a higher percentage of patients with RP-UI and higher variation in comparison to high-volume hospitals (&gt;120 RPs/yr). In comparison to hospitals with low RP volumes throughout the study period, the risk of RP-UI was 29% lower in hospitals shifting from the low-volume to the high-volume category (&gt;120 RPs/yr) and 52% lower in hospitals with a high RP volume throughout the study period (&gt;120 RPs/yr for 5 yr). Conclusions: A focus on increasing hospital RP volumes alone does not seem to be sufficient to reduce the incidence of RP-UI, at least in the short term. Measurement of outcomes, preferably per surgeon, and the introduction of quality assurance programs are recommended. Patient summary: In the Netherlands, centralization of surgery to remove the prostate (RP) because of cancer has not yet improved the occurrence of urinary incontinence (UI) after surgery. Hospitals performing more than 120 RP operations per year had better UI outcomes. However, there was a big difference in UI outcomes between hospitals.</p

Impact of sex differences in co-morbidities and medication adherence on outcome in 25 776 heart failure patients

__Aims:__ Health insurance claims (HIC) databases in the Netherlands capture unselected patient populations, which makes them suitable for epidemiological research on sex differences. Based on a HIC database, we aimed to reveal sex differences in heart failure (HF) outcomes, with particular focus on co-morbidities and medication. __Methods and results:__ The Achmea HIC database included 14 517 men and 11 259 (45%) women with a diagnosis treatment code for chronic HF by January 2015. We related their sex, co-morbidities, and medication adherence (medication possession rate >0.8) with the primary endpoint (PE) of all-cause mortality or HF admission during a median follow-up of 3.3 years, using Cox regression. Median age of men and women was 72 and 76 years, respectively. Prevalence of co-morbidities and use of disease-modifying drugs was higher in men; however, medication adherence was similar. At the end of follow-up, 35.1% men and 31.8% women had reached the PE. The adjusted hazard ratio for men was 1.25 (95% confidence interval: 1.19–1.30). A broad range of co-morbidities was associated with the PE. Overall, these associations were stronger in women than in men, particularly for renal insufficiency, chronic obstructive pulmonary disease/asthma, and diabetes. Non-adherence to disease-modifying drugs was related with a higher incidence of the PE, with similar effects between sexes. __Conclusions:__ In a representative sample of the Dutch population, as captured in a HIC database, men with chronic HF had a 25% higher incidence of death or HF admission than women. The impact of co-morbidities on the outcome was sex dependent, while medication adherence was not

Privacy-preserving dataset combination and Lasso regression for healthcare predictions

Background: Recent developments in machine learning have shown its potential impact for clinical use such as risk prediction, prognosis, and treatment selection. However, relevant data are often scattered across different stakeholders and their use is regulated, e.g. by GDPR or HIPAA. As a concrete use-case, hospital Erasmus MC and health insurance company Achmea have data on individuals in the city of Rotterdam, which would in theory enable them to train a regression model in order to identify high-impact lifestyle factors for heart failure. However, privacy and confdentiality concerns make it unfeasible to exchange these data. Methods: This article describes a solution where vertically-partitioned synthetic data of Achmea and of Erasmus MC are combined using Secure Multi-Party Computation. First, a secure inner join protocol takes place to securely determine the identifiers of the patients that are represented in both datasets. Then, a secure Lasso Regression model is trained on the securely combined data. The involved parties thus obtain the prediction model but no further information on the input data of the other parties. Results: We implement our secure solution and describe its performance and scalability: we can train a prediction model on two datasets with 5000 records each and a total of 30 features in less than one hour, with a minimal difference from the results of standard (non-secure) methods. Conclusions: This article shows that it is possible to combine datasets and train a Lasso regression model on this combination in a secure way. Such a solution thus further expands the potential of privacy-preserving data analysis in the medical domain

Additional file 1: of Outcome measures for oral health based on clinical assessments and claims data: feasibility evaluation in practice

Questionnaire evaluation process data collection. (DOCX 16 kb

Effectiveness of pharmacotherapy in behavioural therapeutic smoking cessation programmes

BACKGROUND: In 2011, pharmacotherapy as a part of smoking cessation treatment was reimbursed through the basic health insurance in the Netherlands. We examine the (cost)-effectiveness of pharmacotherapy added to behavioural therapy. METHODS: An observational study was conducted using data from the suppliers of the smoking cessation programmes together with information on costs from health insurance company Achmea. National suppliers, general practitioners and healthcare centres offered four different programmes. (i) Behavioural support (=therapy); (ii) Behavioural support combined with nicotine replacement therapy (NRT); (iii) Behavioural support combined with smoking cessation aids (=medication) (SCA); (iv) Behavioural support combined with NRT and SCA. The primary independent variable was the programme type, and the primary outcome was whether someone quitted smoking. To examine the effectiveness of the different programmes logistic regression and logistic multilevel analyses were performed. Bootstrapping was used to evaluate cost-effectiveness. RESULTS: The results indicate that behavioural support combined with SCA has more quitters than the reference programme of behavioural support alone, and it also seems the most cost-effective programme for general practitioners and healthcare centres. Behavioural therapy combined with NRT had also more quitters, although the difference with the reference programme was smaller. CONCLUSION: Behavioural support combined with SCA seems the most successful programme. However, as we performed an observational study, firm conclusions about the differences in effectiveness between the programme types cannot be made. Future research should consider the type of smoker (smoking history, amount of cigarettes per day)

Effectiveness of pharmacotherapy in behavioural therapeutic smoking cessation programmes

BACKGROUND: In 2011, pharmacotherapy as a part of smoking cessation treatment was reimbursed through the basic health insurance in the Netherlands. We examine the (cost)-effectiveness of pharmacotherapy added to behavioural therapy. METHODS: An observational study was conducted using data from the suppliers of the smoking cessation programmes together with information on costs from health insurance company Achmea. National suppliers, general practitioners and healthcare centres offered four different programmes. (i) Behavioural support (=therapy); (ii) Behavioural support combined with nicotine replacement therapy (NRT); (iii) Behavioural support combined with smoking cessation aids (=medication) (SCA); (iv) Behavioural support combined with NRT and SCA. The primary independent variable was the programme type, and the primary outcome was whether someone quitted smoking. To examine the effectiveness of the different programmes logistic regression and logistic multilevel analyses were performed. Bootstrapping was used to evaluate cost-effectiveness. RESULTS: The results indicate that behavioural support combined with SCA has more quitters than the reference programme of behavioural support alone, and it also seems the most cost-effective programme for general practitioners and healthcare centres. Behavioural therapy combined with NRT had also more quitters, although the difference with the reference programme was smaller. CONCLUSION: Behavioural support combined with SCA seems the most successful programme. However, as we performed an observational study, firm conclusions about the differences in effectiveness between the programme types cannot be made. Future research should consider the type of smoker (smoking history, amount of cigarettes per day)

An examination of the risk of periodontitis for nonfatal cardiovascular diseases on the basis of a large insurance claims database

Objectives: Although many studies have reported a higher risk of atherosclerotic cardiovascular diseases (ACVD) in people with periodontitis (PD), this has been tested in a few large-scale population-based studies with a longitudinal design. The aim of this study was to investigate whether people with PD status have an increased risk of a nonfatal ACVD event compared to people without PD status. Methods: A cohort of 1.2 million participants from a healthcare insurance claims database was studied longitudinally for a period of 8 years. PD status was derived from PD-related insurance claims and ACVD status from ACVD-related insurance claims. Person-time at risk (PTAR) was calculated from the start of follow-up (01 January 2007) for participants with and without PD status until ACVD or event-free censoring (31 December 2014). Time-dependent Cox proportional hazard models were used to calculate the hazard ratio (HR) and to adjust for shared risk factors (age, sex, socioeconomic position and diabetes mellitus). Results: The prevalence of PD was 20.1%, and the cumulative incidence of nonfatal ACVD events was 7.5%. The univariable and multivariable analyses revealed a limited risk of ACVD for participants with PD status (HR: 1.12; 95% CI 1.10–1.14, HR: 1.06; 95% CI 1.04–1.08, respectively). A subgroup analysis of participants ≤35 and > 35 years of age showed that those ≤35 years of age with PD status had a higher ACVD risk (univariable HR: 1.20; 95% CI 1.05–1.37, multivariable HR: 1.21; 95% CI 1.05–1.39). ACVD risk was not increased in participants >35 years of age with PD status (univariable HR: 0.92; 95% CI 0.91–0.94, multivariable HR: 0.96; 95% CI 0.94–0.98). Conclusions: This study based on a healthcare insurance cohort shows that PD can hardly be regarded as a risk factor for nonfatal ACVD. The increased risk is of minor size, and therefore, the proposed role of PD in the development of ACVD events should be reconsidered. Possibly PD plays a role as a risk factor in younger people due to overlapping genetic risk factors of ACVD and a more aggressive course of PD