Secured and Privacy-Preserving Multi-Authority Access Control System for Cloud-Based Healthcare Data Sharing.

With continuous advancements in Internet technology and the increased use of cryptographic techniques, the cloud has become the obvious choice for data sharing. Generally, the data are outsourced to cloud storage servers in encrypted form. Access control methods can be used on encrypted outsourced data to facilitate and regulate access. Multi-authority attribute-based encryption is a propitious technique to control who can access encrypted data in inter-domain applications such as sharing data between organizations, sharing data in healthcare, etc. The data owner may require the flexibility to share the data with known and unknown users. The known or closed-domain users may be internal employees of the organization, and unknown or open-domain users may be outside agencies, third-party users, etc. In the case of closed-domain users, the data owner becomes the key issuing authority, and in the case of open-domain users, various established attribute authorities perform the task of key issuance. Privacy preservation is also a crucial requirement in cloud-based data-sharing systems. This work proposes the SP-MAACS scheme, a secure and privacy-preserving multi-authority access control system for cloud-based healthcare data sharing. Both open and closed domain users are considered, and policy privacy is ensured by only disclosing the names of policy attributes. The values of the attributes are kept hidden. Characteristic comparison with similar existing schemes shows that our scheme simultaneously provides features such as multi-authority setting, expressive and flexible access policy structure, privacy preservation, and scalability. The performance analysis carried out by us shows that the decryption cost is reasonable enough. Furthermore, the scheme is demonstrated to be adaptively secure under the standard model.

Short term impact of guidelines on vancomycin dosing and therapeutic drug monitoring.

BACKGROUND: After medical center implementation of 2009 ASHP/IDSA guidelines, we evaluated the appropriateness of vancomycin dosing and TDM. OBJECTIVE: Our primary objectives were to assess short term effects on (1) appropriateness of initial vancomycin dosing, (2) appropriateness of sampling of plasma levels, before and after implementation of guidelines. METHOD: The study was conducted in two phases, pre-guideline and post-guideline implementation. The interventions included (1) Nurses and phlebotomist education regarding the appropriate timing of vancomycin sampling, (2) A nomogram for appropriate initial dosing that was distributed to medical staff. Patient demographics, dosing and timing of sampling were collected in eligible patients and assessed for appropriateness. RESULTS: The appropriateness of the prescribed dose increased from 51% (128/253) of patients during the pre period to 78% (155/200) (p < 0.0001) during the post period. Similarly, overall appropriateness of sampling of vancomycin troughs at steady state improved from 36% (63/173) pre to 55% (106/191) (p < 0.03) post. Specifically, the appropriate timing of troughs (within 30 min of the next dose) increased from 37% (64/173) during the pre period to 78% (149/191) during the post period (p < 0.0001). Conclusion Adoption of the guidelines with associated training resulted in significant short term improvement in vancomycin dosing and TDM.

Comparison of beta-lactam and macrolide combination therapy versus fluoroquinolone monotherapy in hospitalized Veterans Affairs patients with community-acquired pneumonia.

Data comparing the treatment outcomes of the two most frequently recommended empirical antibiotic regimens for community-acquired pneumonia (CAP)--combination therapy with an extended-spectrum beta-lactam and a macrolide (BL+M) or fluoroquinolone (F) monotherapy--for patients with severe CAP are sparse. The purpose of this study was to compare empirical BL+M combination therapy with F monotherapy for Veterans Affairs (VA) patients with severe CAP. This retrospective study included patients with CAP who received empirical therapy with BL+M or F between October 1999 and May 2003 in the Upstate New York VA Network. Outcome measures were 14-day mortality, 30-day mortality, and length of hospital stay (LOS). Severe CAP was defined as a class V pneumonia severity index (PSI). During the study period, 261 patients received BL+M and 254 received F. Disease severity was similar for the two treatment groups at admission, and the presence of tachycardia was the only difference noted. For PSI class V patients, there were lower 14-day and 30-day mortality rates with BL+M than with F (14-day rates, 8.2% versus 26.8% [P = 0.02]; 30-day rates, 18.4% versus 36.6% [P = 0.05]). No differences in mortality between treatment groups were noted for the lower PSI classes. The overall median LOS was significantly longer for the BL+M combination group than for the F monotherapy group (6.0 days versus 5.0 days, respectively [P = 0.01]), but no difference in LOS was noted among PSI class V patients. Our study showed that improved outcomes may be realized with BL+M in cases of severe CAP. A randomized clinical study is warranted based on these results.