<p>In the current age of digitalization, smartphone health applications are rapidly increasing. It could be of great help for society to use health apps for regular monitoring of health instead of personally visiting medical consultants. Several health apps exist but their utilization is low mainly owing to usability problems. To enhance usage, it is essential to identify the key parameters that significantly affect the usability of health apps. This insight can help in developing an evaluation model for their usability. Although numerous usability models exist but these models often overlook critical usability aspects such as trust, security, response time and interruptibility and diverse stakeholder needs specific to health apps. This research emphasized identifying and prioritizing usability parameters of health apps using a hierarchical model. First, to determine the key parameters influencing the usability of health apps, a thorough analysis of relevant literature was carried out. Secondly, only the parameters with the most significant effects among the recognized ones were considered. A survey was conducted to identify the key usability parameters. The survey instrument was distributed among 195 subjects, including medical doctors, pharmacists, paramedical staff, medical students, designers of health apps, and the general public. Lastly, a second instrument was used with 49 participants to conduct pairwise comparisons among the parameters and sub-parameters, ranking them according to their relative importance. The identified and prioritized sub-parameters were grouped into four major categories. Among these, efficiency was recognized as the key criterion while effectiveness was considered the least significant criterion. The comparison revealed that the proposed model is more comprehensive regarding usability than existing models.</p>