Trends in population attributable fraction of modifiable risk factors for cardiovascular diseases across three decades.

AIM: To evaluate temporal trends, across three decades, in the population attributable fractions (PAFs) of modifiable risk factors for 5-year risk of cardiovascular diseases (CVDs). METHODS: Within population-based Rotterdam Study, we defined three time-groups of individuals without established CVD at 'baseline' with a mean age of 70 years, and followed for five years: Epoch 1990s (1989-1993, N=6195), Epoch 2000s (1997-2001, N=5572) and Epoch 2010s (2009-2014, N=5135). The prevalence of risk factors and related relative risks were combined to quantify PAFs. RESULTS: The PAF of the six risk factors combined for global CVD was 0.57 (95% confidence interval [CI] 0.47 to 0.65), 0.52 (0.39 to 0.62) and 0.39 (0.18 to 0.54) in three respective epochs. Hypertension contributed the highest PAF to global CVD in Epoch 1990s (0.37, 95% CI: 0.28 to 0.44) and 2000s (0.34, 95% CI: 0.22 to 0.43), while smoking was the largest contributor in Epoch 2010s (0.20, 95% CI: 0.06 to 0.32). Dyslipidemia changed population-level coronary heart disease risk over time. For stroke, hypertension became a less significant contributor over time, but smoking became a larger contributor. For heart failure, all risk factors showed non-significant PAFs in Epoch 2010s. PAFs related to individual risk factor varied among women and men. CONCLUSION: Six modifiable risk factors to population-level global CVD risk decreased over time, but still explained 39% of total CVD in the latest decade. PAFs changed considerably for hypertension, dyslipidemia, and smoking. Risk factors had different PAFs for different CVDs with pronounced sex differences.

The contribution of the individual cardiovascular risk factors to population CVD risk considerably changed over the past 3 decades, especially for hypertension, dyslipidemia, and smoking. Traditional modifiable risk factors exerted declining contributions to population burden of total CVD over the past three decades, suggesting good progress in CVD prevention. Nonetheless, in the latest decade, unfavorable risk factors accounted for 39% of total CVD burden. Sex differences in the contributions of abdominal obesity, diabetes and smoking to cardiovascular outcomes were observed.

Pressure-Compensated Fiber-Optic Photoacoustic Sensors for Trace SO2 Analysis in Gas Insulation Equipment.

A high-sensitivity fiber-optic photoacoustic sensor with pressure compensation is proposed to analyze the decomposition component SO2 in high-pressure gas insulation equipment. The multiple influence mechanism of pressure on photoacoustic excitation and cantilever detection has been theoretically analyzed and verified. In the high-pressure environment, the excited photoacoustic signal is enhanced, which compensates for the loss of sensitivity of the cantilever. A fiber-optic F-P cantilever is utilized to simultaneously measure static pressure and dynamic photoacoustic wave, and a spectral demodulation method based on white light interference is applied to calculate the optical path difference of the F-P interferometer (FPI). The real-time pressure is judged through the linear relationship between the average optical path difference of FPI and the pressure, which gives the proposed fiber-optic photoacoustic sensor the inherent advantages of being uncharged and resistant to electromagnetic interference. The average optical path difference of FPI is positively related to pressure, with a responsivity of 0.6 µm/atm, which is based on changes in the refractive index of gas. In the range of 1-4 atm, the SO2 sensor has a higher detection sensitivity at high-pressure, which benefits from the pressure compensation effect. With the pressure environment of gas insulation equipment at 4 atm as the application background, the SO2 gas is tested. The detection limit is 20 ppb with an averaging time of 400 s.

Fiber-Optic Photoacoustic Gas Microsensor Dual Enhanced by Helmholtz Resonator and Interferometric Cantilever.

A high-sensitivity fiber-optic photoacoustic (PA) gas microsensor is demonstrated with dual enhancement based on acoustics and detection. Due to the characteristic of small size, a Helmholtz resonator is integrated into a miniature PA sensor. The acoustically amplified PA signal is detected by a high-sensitivity fiber Fabry-Perot (F-P) interferometric cantilever. The first-order resonant frequencies of the interferometric cantilever and Helmholtz resonator are matched by subtle adjustments. The weak PA signal is significantly enhanced in a volume of only 0.35 mL, which breaks the volume limitation of the resonance modes in traditional PA sensing systems. To improve the resolution of the microsensor, a white light interferometry (WLI)-based spectral demodulation algorithm is utilized. The experimental results indicate that the minimum detection limit of acetylene (C2H2) drops to about 15 ppb with an averaging time of 100 s, corresponding to the normalized noise equivalent absorption (NNEA) coefficient of 2.7 × 10-9 W·cm-1·Hz-1/2. The dual resonance enhanced fiber-optic PA gas microsensor has the merits of high sensitivity, intrinsic safety, and compact structure.

Rapid Photoacoustic Exhaust Gas Analyzer for Simultaneous Measurement of Nitrogen Dioxide and Sulfur Dioxide.

A rapid photoacoustic (PA) exhaust gas analyzer is presented for simultaneous measurements of nitrogen dioxide (NO2) and sulfur dioxide (SO2). A laser diode (LD) emitting at 450 nm and a light-emitting diode (LED) with a peak wavelength of 275 nm operated simultaneously, producing PA signals of NO2 and SO2, respectively. The LD and LED were modulated at different frequencies of 2568 and 2570 Hz, and their emission light beams were transmitted through two resonant tubes in a differential PA cell (DPAC), respectively. A self-made dual-channel digital lock-in amplifier was used to realize the simultaneous detection of dual-frequency PA signals. Cross interference between the PA signals at the two different frequencies was reduced to 0.02% by using a lock-in amplifier. In order to achieve a rapid dynamic measurement, gas sampling was accelerated by an air pump. The use of mufflers and the differential PA detection technique significantly reduced the gas sampling noise. When the gas flow rate was 1000 sccm, the response time of the PA dual-gas analyzer was 8 and 17 s for NO2 and SO2, respectively. The minimum detection limits of NO2 and SO2 were 1.7 and 26.1 ppb when the averaging time of the system was 10 s, respectively. Due to the wide spectral bandwidth of the LED, NO2 produced an interference to the detection of SO2. The interference was reduced by the precise detection of NO2. Since the radiations of the LD and LED passed through two different PA tubes, the impact of NO2 photochemical dissociation caused by UV LED luminescence on NO2 gas detection was negligible. The sharing of the PA cell, the gas lines, and the signal processing modules significantly reduced the size and cost of the PA dual-gas analyzer.

Fiber-Optic Photoacoustic CO Sensor for Gas Insulation Equipment Monitoring Based on Cantilever Differential Lock-In Amplification and Optical Excitation Enhancement.

A fiber-optic photoacoustic CO sensor for gas insulation equipment is proposed, which relies on F-P interferometric cantilever-based differential lock-in amplification and optical multipass excitation enhancement. The sensor has excellent characteristics of high sensitivity, antielectromagnetic interference, fast response, and long-distance detection. The photoacoustic pressure waves in the two resonators of the differential photoacoustic cell (DPAC) are simultaneously detected by two fiber-optic interferometric cantilevers and processed differentially; thereby, the gas flow noise is effectively suppressed. Based on the comprehensive analysis of the superposition of photoacoustic excitation and multipass absorption, the diameter of the resonator is determined to be 6 mm. The optical power emitted by the 1566.6 nm distributed feedback laser is increased to 500 mW by an erbium-doped fiber amplifier. The near-infrared light is reflected 30 times in the multipass cell, which improves the order of magnitude of optical effective excitation. Due to the low sound velocity of SF6 gas, the resonant frequency of the DPAC with a resonator length of 80 mm is 760 Hz. The response time to CO/SF6 gas is 93 s with a flow rate of 500 sccm. The detection limit of the CO sensor is 53 ppb, which realizes the accurate and timely perception of the SF6 decomposition derivative CO and provides technical support for trouble-free operation of gas insulation equipment.

Dense Multibutterfly Spots-Enhanced Miniaturized Optical Fiber Photoacoustic Gas Sensor.

A miniaturized optical fiber photoacoustic gas sensor enhanced by dense multibutterfly spots is reported for the first time. The principle of space light transmission of neglecting paraxial approximation is theoretically analyzed for designing a dense multibutterfly spots-based miniature multipass cell. In a multipass photoacoustic tube with a diameter of 16 mm, the light beam is reflected about a hundred times. The light spots on the mirror surfaces at both ends of the photoacoustic tube form a dense multibutterfly distribution. The volume of the micro multipass gas chamber is only 5.3 mL. An optical fiber cantilever based on F-P interference is utilized as a photoacoustic pressure detector. Compared with that of the single-pass structure, the gas detection ability of the photoacoustic system with dense multibutterfly spots is improved by about 50 times. The proposed miniaturized sensor realizes a detection limit of 3.4 ppb for C2H2 gas with an averaging time of 100 s. The recognized coefficients of minimum detectable absorption (αmin) and normalized noise equivalent absorption are 1.9 × 10-8 cm-1 and 8.4 × 10-10 W cm-1 Hz-1/2, respectively.

Differential Cantilever Enhanced Fiber-Optic Photoacoustic Sensor for Diffusion Gas Detection.

Aiming at the problem of the fiber-optic photoacoustic (PA) sensor being easily disturbed by external vibration and noise, a differential cantilever enhanced fiber-optic PA sensor is proposed for diffusion gas detection. The sensor comprises two PA tubes with the same structure and a pair of differential interferometric cantilevers. The two PA tubes are symmetrically distributed. The laser is incident on the PA tube as the signal channel to excite the PA pressure wave. Another tube without incident laser is used as the reference channel to suppress external disturbance. The external interference signals and PA signals superimposed with disturbance are detected by the differential cantilevers from the two channels. The signals are simultaneously restored by a single white-light interferometry demodulator, which multiplexed the spectral frequency domain of the superimposed interference spectrum. The experimental results show that the suppression effect of the differential cantilever enhanced PA sensor on ambient noise is improved by 80%, compared to the traditional single-cantilever sensor. The external cofrequency disturbance is suppressed by 20.9 dB. The minimum detection limit to acetylene (C2H2) downs to about 60 ppb with an integration time of 100 s. The sensor has excellent antivibration and electromagnetic interference ability.

Ultrahigh-speed phase demodulation of a Fabry-Perot sensor based on fiber array parallel spectral detection.

An ultrahigh-speed phase demodulation system was designed for the Fabry-Perot (F-P) interferometric sensor based on fiber array parallel spectral detection. A high-power amplified spontaneous emission (ASE) source served as the broadband detection light. The spectrum generated by the dispersion of the F-P interference light through an arrayed waveguide grating (AWG) was incident into the fiber array and was detected in parallel by 48 photodiodes. The 48-channel signals were acquired synchronously and processed in real time to achieve a phase demodulation for the F-P cavity at 200 kHz. As a result, a low-resolution spectral detection and demodulation system was constructed with high speed. The length demodulation range of the F-P cavity was 60-700 µm, and the demodulation resolution was as high as 0.22 nm. The designed high-sensitivity demodulator is expected to be used for ultrasonic and high-frequency vibration detection.

High-Precision Multipass Fiber-Optic Photoacoustic Gas Analyzer Based on 2f/1f Wavelength Modulation Spectroscopy.

A self-calibration fiber-optic photoacoustic (PA) gas analyzer based on 2f/1f wavelength modulation spectroscopy (WMS) is proposed, which utilizes gas and solid multipass absorption enhancement. The laser light is incident obliquely on the cell wall, and one end of the cell is equipped with a highly reflective mirror. The gas analyzer takes full advantage of the miniature multipass PA cell, which enhances the absorption of gas and solid simultaneously. As a result, the double absorption enhancement of 1f and 2f PA signals are realized. A dual-channel lock-in white-light interferometer based on fiber-optic PA demodulation is designed to simultaneously extract the 1f and 2f PA signals detected by the silicon cantilever. The experimental results of methane gas detection show that the minimum detection limit (MDL) of the PA gas analyzer is 20 ppb when the integration time is 60 s. Moreover, the detection error of gas concentration is within 3% when the laser power is reduced by half. The fiber-optic PA gas analyzer eliminates the influence of changes in the laser power and optical path loss, which can be used for the high-precision detection of trace gases.

High-Precision Photoacoustic Nitrogen Dioxide Gas Analyzer for Fast Dynamic Measurement.

A high-precision photoacoustic (PA) gas analyzer for fast dynamic measurement of ambient nitrogen dioxide (NO2) was developed. The PA analyzer used a differential PA cell combined with two mufflers to achieve rapid gas flow gas detection. A high-power laser diode (LD) with a center wavelength of 450 nm was used as the PA signal excitation source. To reduce the saturated absorption effect of NO2, ambient air was pumped into the analyzer at a flow rate of 900 sccm. Two mufflers were combined with the differential PA cell to reduce the noise caused by the airflow and pump. The parameters of the mufflers were optimized by using a finite element method. The experimental results showed that the gas flow noise was suppressed by 95%. The response time of the PAS analyzer was 34 s. The detection limits of the analyzer were 0.64 and 0.17 ppb when the integration times were 1 and 15 s, respectively. A 120 h continuous monitoring result was compared with the data from the National Environmental Monitoring Station to demonstrate the high reliability of the analyzer.

Ultrahigh Sensitive Trace Gas Sensing System with Dual Fiber-Optic Cantilever Multiplexing-Based Differential Photoacoustic Detection.

An ultrahigh sensitive trace gas sensing system was presented with dual cantilever-based differential photoacoustic detection. By combining the double enhancement of multipass absorption and optical differential detection, the gas detection sensitivity was significantly improved. The dual-channel synchronous photoacoustic detection was realized by fiber-optic Fabry-Perot interference spectrum multiplexing. The photoacoustic signals detected by two fiber-optic cantilever microphones installed in a differential photoacoustic cell (DPAC) were out of phase, while the detected gas flow noises were in phase. The optical differential detection method achieved both highly sensitive optical interference measurement and differential noise suppression. In the multipass configuration, the interaction path between excitation light and target gas achieved 4.1 m, which improved the photoacoustic signal by an order of magnitude compared with a single reflection. The maximum gas flow allowed by the system based on the DPAC was 250 sccm, which realized the dynamic monitoring of H2S in the SF6 background. The detection limit for H2S in SF6 background was 5.1 ppb, which corresponds to the normalized noise equivalent absorption coefficient of 9 × 10-10 cm-1 W Hz-1/2.

Fiber-Optic Photoacoustic Gas Sensor with Multiplexed Fabry-Pérot Interferometric Cantilevers.

A fiber-optic photoacoustic (PA) gas sensor with multiplexed Fabry-Pérot (F-P) interferometric cantilevers is demonstrated. A compact cylindrical nonresonant PA tube with a volume of only 0.45 mL is designed. The PA signal is measured by two symmetrically installed fiber-optic interferometric cantilever microphones (FOICMs) to improve the signal-to-noise ratio (SNR). For multiplexing the two cantilevers by a single demodulation system, a dual cavity length synchronous measurement method based on total-phase demodulation algorithm with ultrahigh resolution is developed. The PA signal detection is realized by the second-harmonic wavelength modulation spectroscopy (2f-WMS) technique. The sensor performance is verified by conducting the detection of trace acetylene (C2H2). The normalized noise equivalent absorption (NNEA) coefficient is 2.5 × 10-9 cm-1·W·Hz-1/2, and the minimum detection limit (MDL) downs to about 0.2 ppm with an averaging time of 1 s. The fiber-optic PA gas sensor has characteristics of high resolution and immunity to electromagnetic and vibration interference. Furthermore, the technical scheme of the multiplexed cantilever demodulation shows great potential for remote multipoint monitoring of gases in harsh environments.

Integrated near-infrared fiber-optic photoacoustic sensing demodulator for ultra-high sensitivity gas detection.

An integrated near-infrared fiber-optic photoacoustic sensing demodulator was established for ultra-high sensitivity gas detection. The demodulator has capacities of interference spectrum acquisition and calculation, laser modulation control as well as digital lock-in amplification. FPGA was utilized to realize all the control and signal processing functions, which immensely improved the integration and stability of the system. The photoacoustic signal detection based on fiber-optic Fabry-Perot (F-P) acoustic sensor was realized by applying ultra-high resolution spectral demodulation technique. The detectable frequency of photoacoustic signal achieved 10 kHz. The system integrated lock-in amplification technology, which made the noise sound pressure and dynamic response range of sound pressure detection reached 3.7 µPa/√Hz @1 kHz and 142 dB, respectively. The trace C2H2 gas was tested with a multi-pass resonant photoacoustic cell. Ultra-high sensitivity gas detection was accomplished, which was based on high acoustic detection sensitivity and the matching digital lock-in amplification. The system detection limit and normalized noise equivalent absorption (NNEA) coefficient were reached 3.5 ppb and 6.7 × 10-10 cm-1WHz-1/2, respectively. The devised demodulator can be applied for long-distance gas measurement, which depends on the fact that both the near-infrared photoacoustic excitation light and the probe light employ optical fiber as transmission medium.

Dynamic detection of ppb-level SO2 based on a differential photoacoustic cell coupled with UV-LED.

We design a photoacoustic (PA) SO2 sensor based on the coupling of a differential photoacoustic cell (DPAC) and cost-effective UV-LED, which realized the dynamic monitoring of SO2 gas at the ppb level. Aiming at the limitation of UV-LED divergence, a light source combination module with high condensing efficiency was devised based on a lens through theoretical derivation and experimental analysis. The PA signal with the optimum matching of the lens was 20-times larger than the direct coupling of the UV-LED. Due to the excellent beam collimation effect of the lens assembly, the background interference was only 1 ppm. In addition, the DPAC gathered the merits of doubling the PA signal and reducing the flow noise interference. The analysis of Allan-Werle deviation showed that the detection limit of SO2 was 1.3 ppb with the averaging time of 100 s.

Excess Deaths of Gastrointestinal, Liver, and Pancreatic Diseases During the COVID-19 Pandemic in the United States.

Objectives: To evaluate excess deaths of gastrointestinal, liver, and pancreatic diseases in the United States during the COVID-19 pandemic. Methods: We retrieved weekly death counts from National Vital Statistics System and fitted them with a quasi-Poisson regression model. Cause-specific excess deaths were calculated by the difference between observed and expected deaths with adjustment for temporal trend and seasonality. Demographic disparities and temporal-spatial patterns were evaluated for different diseases. Results: From March 2020 to September 2022, the increased mortality (measured by excess risks) for Clostridium difficile colitis, gastrointestinal hemorrhage, and acute pancreatitis were 35.9%; 24.8%; and 20.6% higher than the expected. For alcoholic liver disease, fibrosis/cirrhosis, and hepatic failure, the excess risks were 1.4-2.8 times higher among younger inhabitants than older inhabitants. The excess deaths of selected diseases were persistently observed across multiple epidemic waves with fluctuating trends for gastrointestinal hemorrhage and fibrosis/cirrhosis and an increasing trend for C. difficile colitis. Conclusion: The persistently observed excess deaths of digestive diseases highlights the importance for healthcare authorities to develop sustainable strategies in response to the long-term circulating of SARS-CoV-2 in the community.

Multi-pass Differential Photoacoustic Sensor for Real-Time Measurement of SF6 Decomposition Component H2S at the ppb Level.

We designed and implemented a photoacoustic (PA) sensor for H2S detection in SF6 background gas based on a multi-pass differential photoacoustic cell (MDPC) and a near-infrared distributed feedback (DFB) laser. In the MDPC apparatus, two resonators with identical geometric parameters were vertically and symmetrically embedded. The differential processing algorithm of two phase-reversed signals realized the effective enhancement of the PA signal and suppressed the flow noise in the dynamic sampling process. In addition, the λ/4 buffer chamber in the MDPC was utilized as a muffler to further reduce the flow noise and realize the dynamic detection of H2S. The collimated excitation light was reflected 30 times in a multi-pass structure constituted of two gold-plated concave mirrors, and an absorption path length of 4.92 m was achieved. Due to the high gas density of SF6, the relationship between the signal-to-noise ratio (SNR) and the gas flow was different between SF6 and N2 background gases. The maximum flow rate of the characteristic gas components detected in the SF6 background is 150 standard cubic centimeters per minute (SCCM), which is lower than 350 SCCM in N2. The linearity property was analyzed, and the results show that the sensitivity of the sensor to H2S in the SF6 background was 27.3 µV/ppm. With the structure, parameters, temperature, gas flow, and natural frequency of the MDPC been optimized, a minimum detection limit (MDL) of 11 ppb was reached with an averaging time of 1000 s, which furnished an effective preventive implement for the safe operation of gas insulation equipment.

Female Reproductive Factors and Risk of New-Onset Heart Failure: Findings From UK Biobank.

BACKGROUND: A comprehensive evaluation of woman-specific risk factors in relation to incident heart failure (HF) is limited. OBJECTIVES: This study sought to investigate the association of multiple female reproductive factors with the risk of HF. METHODS: Between 2007 and 2010, 229,026 women (mean age: 56.5 years) without prevalent HF from the UK Biobank cohort were included and followed until December 2020. The relation between (self-reported) reproductive factors and HF was analyzed using Cox proportional hazards models with adjustment for potential confounding. RESULTS: Menarche at age <12 years, compared to age 12-13 years, carried a 9% larger risk of HF (HR: 1.09 [95% CI: 1.01-1.18]). Younger age at menopause was associated with a higher risk of HF (HRage <45 y vs 50-51 y: 1.15 [95% CI: 1.03-1.28]; HRage 45-49 y vs 50-51 y: 1.11 [95% CI: 1.01-1.23]). Younger maternal age at first live birth (HRage <21 y vs 24-26 y: 1.42 [95% CI: 1.28-1.59]; HRage 21-23 y vs 24-26 y: 1.14 [95% CI: 1.03-1.26]) and at last live birth (HRage <26 y vs 29-31 y: 1.19 [95% CI: 1.07-1.33]) were associated with higher risk of HF. Compared to women with 1 or 2 children, having 3 or 4 children (HR: 1.09 [95% CI: 1.02-1.17]) or >4 children (HR: 1.24 [95% CI: 1.05-1.47]) was associated with higher HF risk. Experiencing miscarriages or abortions was not significantly associated with incident HF, whereas experiencing 1 stillbirth and recurrent stillbirths conferred a 20% and 43% larger risk of HF, respectively, compared to no stillbirth. CONCLUSIONS: The findings emphasize the importance of female reproductive history in the assessment of HF risk.

Latent class analysis-based subgroups and response to corticosteroids in hospitalised community-acquired pneumonia patients: a validation study.

In patients with community-acquired pneumonia, LCA can identify robust prognostic subgroups based on clinical and inflammatory parameters. Yet, these subgroups have not proven robust in predicting response to adjunctive dexamethasone treatment. https://bit.ly/3O5eaxz.

Arthroscopic versus Open Distal Hemitrapeziectomy without Interposition: 2-Year Results of a Randomized Controlled Trial.

BACKGROUND: Distal hemitrapeziectomy is suggested as an alternative for total trapeziectomy for carpometacarpal thumb joint osteoarthritis, when the scaphotrapeziotrapezoidal joint is unaffected. This can be performed as an arthroscopic or open procedure, with suggested advantages for the less invasive arthroscopic technique. To determine which technique has better outcome on subjective and objective measures, the authors performed a prospective, randomized, controlled trial. METHODS: The authors randomized 90 thumbs in the open ( n = 45) and arthroscopic ( n = 45) groups and evaluated results preoperatively and at 3-, 12- and 24-month follow-up. The primary outcome was the Patient-Rated Wrist and Hand Evaluation (PRWHE) to assess pain and function. Also, the authors evaluated pinch, grip, and range of motion, together with return to work, satisfaction, and complications. RESULTS: Full follow-up was obtained in 62 thumbs (open group, n = 32; arthroscopic group, n = 30). For both groups, the PRWHE improved from preoperatively to 12- and 24-month follow-up. Also, grip power, key pinch, and tip pinch improved at final follow-up for both groups. Between groups, there were no clinically important differences between PRWHE, power of grip or pinch, and range of motion. Operation time was shorter for the open group; also, return to work was slightly shorter after open surgery. Satisfaction was comparable between groups. CONCLUSIONS: This study shows good functional improvement and pain reduction obtained with a hemitrapeziectomy. No arthroscopic benefits could be substantiated in the results. Because of shorter operation time for the open procedure, and because of equal outcomes compared to the arthroscopic technique, we prefer open hemitrapeziectomy. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, I.

Sample size calculation for clinical trials analyzed with the meta-analytic-predictive approach.

The meta-analytic-predictive (MAP) approach is a Bayesian method to incorporate historical controls in new trials that aims to increase the statistical power and reduce the required sample size. Here we investigate how to calculate the sample size of the new trial when historical data is available, and the MAP approach is used in the analysis. In previous applications of the MAP approach, the prior effective sample size (ESS) acted as a metric to quantify the number of subjects the historical information is worth. However, the validity of using the prior ESS in sample size calculation (i.e., reducing the number of randomized controls by the derived prior ESS) is questionable, because different approaches may yield different values for prior ESS. In this work, we propose a straightforward Monte Carlo approach to calculate the sample size that achieves the desired power in the new trial given available historical controls. To make full use of the available historical information to simulate the new trial data, the control parameters are not taken as a point estimate but sampled from the MAP prior. These sampled control parameters and the MAP prior based on the historical data are then used to derive the statistical power for the treatment effect and the resulting required sample size. The proposed sample size calculation approach is illustrated with real-life data sets with different outcomes from three studies. The results show that this approach to calculating the required sample size for the MAP analysis is straightforward and generic.