A health monitoring system, and methods of use and manufacture thereof are disclosed. The health monitoring system may include a computing system and a diagnostic test coupled to a diaper. The diagnostic test may include one or more sensors configured to produce a visual indication of one or more analytes contained in a sample produced by a subject. The diagnostic test may include a machine- readable code. The computing system may be configured to read the machine- readable code to allow an application running on the computing system to automatically perform at least one task related to a production of a data point based on the visual indication. The health monitoring system may aid in identifying a potential abnormal health condition of the subject by providing automatic longitudinal analysis of analytes contained in samples produced by the subject over a period of time.