Modifying Without a Trace: High-level Audit Guidelines are Inadequate for Electronic Health Record Audit Mechanisms

J. King, B. Smith, L. Williams, "Modifying Without a Trace: General Audit Guidelines are Inadequate for Electronic Health Record Audit Mechanisms", Proceedings of the International Health Informatics Symposium (IHI 2012), pp. 305-314, 2012.

Abstract

Without adequate audit mechanisms, electronic health record (EHR) systems remain vulnerable to undetected misuse. Users could modify or delete protected health information without these actions being traceable. The objective of this paper is to assess electronic health record audit mechanisms to determine the current degree of auditing for non-repudiation and determine if high-level audit guidelines adequately address non-repudiation. We qualitatively assess three open-source EHR systems. In our high-level analysis, we derive a set of 16 non-specific auditable event types that affect non-repudiation. We find that the EHR systems audit an average of 12.5% of non-specific event types. In our lower-level analysis, we generate 58 black-box test cases based on specific auditable events derived from the Certification Commission for Health Information certification criteria. We find that only 4.02% of these test executions pass. Additionally, 20% of tests fail in all three EHR systems on actions including the modification of patient demographics, assignment of user privileges, and change of user passwords. The ambiguous nature of non-specific auditable event types may explain the overall inadequacy of auditing for non-repudiation. EHR system developers should focus on specific auditable events for managing protected health information instead of non-specific auditable event types derived from generalized guidelines.

1. Introduction

Without adequate audit systems to ensure accountability, electronic health record (EHR) systems remain vulnerable to undetected misuse, both malicious and accidental. Users could modify or delete protected health information without these actions being traceable to the modifier. According to Chuvakin and Peterson^[3], “If [an organization’s information technology] isn’t accountable, the organization probably isn’t either.” Patients need to trust the privacy practices and accountability of healthcare organizations. Administering software audit mechanisms forms a basis for privacy-driven and accountability-driven policy and regulations, including government regulations^[8]. The United States Health Insurance Portability and Accountability Act of 1996 (HIPAA) Security and Privacy Rule states that one must implement, “mechanisms that record and examine activity in information systems that contain or use electronic protected health information”^[5].

Storing an accurate history of user interaction with a software application and its underlying data helps build a sense of accountability, since a user cannot expressly deny performing certain actions that were recorded by the audit mechanism. In the case of a medical mistake, audit mechanisms can provide a record by which healthcare practitioners can exonerate themselves from legal action by demonstrating that they prescribed the correct drug at a certain time, or that a certain test result was, in fact, what they claim it was. The health informatics field needs standards that address the implementation of software audit mechanisms to monitor access and information disclosure, including details of what should be logged, how it should be logged, and when logged information should be monitored.

The objective of this paper is to assess electronic health record audit mechanisms to determine the current degree of auditing for non-repudiation and determine if high-level audit guidelines adequately address non-repudiation. In performing this study, we investigate the following questions:

• R1: What events should be included in an EHR log file for non-repudiation?
• R2: What are the strengths and weaknesses of software auditing mechanisms in EHR systems?

Software audit log files may include system logs and server logs that assist with debugging and troubleshooting. For this paper, we focus on user activity logs that contain data related to user actions within an EHR system for the purpose of audit and user accountability. In this study, we first perform a high-level analysis of EHR audit mechanisms by deriving a set of 16 general assessment criteria, derived from four academic and professional sources of non-specific auditable events (such as “view data” and “create data”). Next, we perform a lower-level analysis by deriving 58 audit-related black-box test cases to assess specific user actions (such as “view diagnosis data” and “view patient demographics”) in an EHR system. By assessing each EHR’s audit mechanism at both the high- and low-levels, our goal is to compare and contrast the results and suggest techniques for healthcare software developers to strengthen EHR audit mechanisms.

The remainder of this paper is organized as follows. Section 2 briefly discusses background information related to this study and some key terms and definitions. Section 3 discusses related work with audit mechanisms. Section 4 describes the formulation of our high-level and low-level assessment criteria for analyzing non-repudiation in EHR systems. Section 5 presents the open-source EHR systems studied and presents our case studies of evaluating the open-source EHR audit mechanisms. Section 6 discusses the implications and significance of our evaluations. Section 7 presents limitations of our work. Section 8 presents our discussion. Section 9 presents future work in the field of EHR audit mechanisms. Finally, Section 10 summarizes our findings and concludes the paper.

2. Background

The United States Department of Justice’s Global Justice Information Sharing Initiative defines:

• non-repudiation – a technique used to ensure that someone performing an action on a computer cannot falsely deny that they performed that action. Non-repudiation provides undeniable proof that a user took a specific action^[10].

With software systems that manage protected, sensitive data (including EHR systems), a more-specific definition of non-repudiation is needed. We further define the following term based on the definition of non-repudiation above:

• user-based non-repudiation – a techniques used to ensure that an authenticated user accountholder performing an action within a software system cannot falsely deny that they performed that action.

Böck, et al., identify four primary concerns regarding software audit mechanism reliability^[1]:

• storage confidentiality – malicious users should not be able to access log entries
• machine-based non-repudiation – log files can be traced to a specific machine to identify the source of the audit entries
• application-based non-repudiation – log entries can be traced to trusted software applications such that malicious users cannot manually create fake log entries
• transmission confidentiality – accuracy and integrity of log file data is preserved during transmission

Satisfying these concerns is not a simple task, especially for software developers who may implement software audit mechanisms without proactively considering the protection and reliability of the data contained within the log files. Böck, et al., suggest that these four concerns should be considered as a core set of requirements for any software audit mechanism^[1]. Yet actually implementing the software and hardware infrastructure to fulfill these requirements may prove challenging. Combined with limited resources and a concern for user-based non-repudiation, the difficult task of satisfying these requirements may lead some system architects and software developers to abandon the idea of a reliable software audit mechanism in favor of a simplified, more vulnerable one based upon limited storage, unprotected log files, and weak non-repudiation.

One motivation for implementing EHR audit mechanisms for user-based non-repudiation involves the mitigation of insider attack. An insider attack occurs when employees of an organization with legitimate access to their organizations' information systems use these systems to sabotage their organizations' IT infrastructure or commit fraud^[9]. Researchers at the Software Engineering Institute at Carnegie Mellon University released a comprehensive study on insider threats that reviewed 49 cases of Insider IT Sabotage between 1996 and 2002^[9]. According to the study:

• 90% of insider attackers were given administrative or high-level privileges to the target system.
• 81% of the incidents involved losses to the organization, with dollar amounts estimated between "five hundred dollars" and "tens of millions of dollars."
• The majority of attacks occurred after the employees were terminated from the organization.
• Lack of access controls facilitated IT sabotage

Although federal laws, such as HIPAA, provide legal sanction against tampering with or stealing medical records, we cannot assume that employees working within a medical organization will always follow the rules.