This is a retrospective, observational study using routinely collected information collected by Alberta Health Services. The study will identify patients with chronic disease, defined by one or more of the following conditions; diabetes mellitus, heart failure, coronary artery disease, chronic kidney disease, or chronic lung disease. Adult residents of Alberta with a chronic disease of interest present upon hospital admission and who survive to hospital discharge will be included in the study cohort. The primary outcome will be the composite of hospital readmission or death within 30 days of discharge. Secondary outcomes will include components of the composite, length of stay, patient experiences related to their hospital to home transition of care, and processes of care. Multi-level interrupted time series analysis will be used to compare outcomes before versus after implementation of the Connect Care CIS.

The design of the protocol is a multiple-baseline interrupted time series (ITS) analysis to assess effects of the CIS on patient outcomes with five pre-specified NCDs (diabetes mellitus, coronary artery disease, heart failure, chronic kidney disease, and chronic lung disease) before versus after implementation at each cluster of sites, accounting for pre-existing trends in outcomes and correlation between different time points and sites. The primary outcome will be unplanned hospital readmission and death within 30 days of discharge. Secondary outcomes will include readmission and death as individual outcomes, length of hospital stay, processes of care, and measures of patient experience with care transitions.

The study uses retrospective administrative, clinical, and patient experience data collected between 2019 and 2024, covering periods before and after clinical information system implementation at each site. All observations will be recorded prior to study initiation and will be analyzed retrospectively within a multiple baseline interrupted time series framework.

Inclusion Criteria:

• Adults aged 18 years or older at the time of hospital admission.
• Residents of Alberta eligible to receive acute-care services in AHS facilities.
• Hospitalized for any cause during the study period (5 years pre-implementation and 2 years post-implementation of the CIS).
• Meet the validated case definition for one or more of the five key NCDs (diabetes mellitus, chronic kidney disease, coronary artery disease, heart failure, or chronic lung disease) based on ICD codes, laboratory measures, or pharmacy records during standardized lookback periods (up to 5 years for diagnoses; up to 1 year for labs/pharmacy).
• Have a qualifying date for the NCD(s) that occurs prior to or during the index hospital admission.
• Eligible for inclusion in the primary and patient experience outcomes if they survive to hospital discharge.
• May enter multiple sub-cohorts if more than one NCD is present.

Exclusion Criteria:

• Individuals younger than 18 years at the time of hospital admission.
• Non-residents of Alberta or individuals not eligible for care within AHS facilities.
• Hospitalizations that end in death (excluded from analyses of the primary outcome and patient experience measures).
• Patients without evidence of any of the five key NCDs during the lookback period or at the index hospital admission.
• Admissions outside the study period or admissions for which necessary administrative, laboratory, or pharmacy data are unavailable.

The study population consists of adult Alberta residents receiving acute-care services in Alberta Health Services (AHS) facilities who have one or more of five key noncommunicable diseases: diabetes mellitus, chronic kidney disease, coronary artery disease, heart failure, or chronic lung disease. Participants are identified from routinely collected administrative, laboratory, and pharmacy datasets, with hospital admissions included regardless of most responsible diagnosis. The population is broadly representative of adults with chronic conditions experiencing transitions from hospital to home across the province. Patient experience survey data are available for a random 10% sample of eligible discharges.

Investigators are not able to make study data available due to contractual requirements of the data custodian - Alberta Health Services. Other researchers may request IPD for the study from the data custodian through the Alberta SPOR Support Unit: https://absporu.ca/research-services/service-application/