In this paper, we determine the performances of an Optical Code Division Multiple Access (OCDMA) based wireless transmission system for indoor healthcare monitoring application. We consider line of sight communication links between multiple emitters placed on monitored patients and a base station located at the environment ceiling. We first establish an analytical expression of error probability for fixed patient positions, considering On-Off Keying modulation and Optical Orthogonal Codes (OOC). After validation of the theoretical results, we then study the performance degradation because of patient mobility, in terms of outage probability. The impact of mobility is analyzed as a function of patient number, OOC length end environment dimensions. Thanks to our theoretical approach, we show that it is possible to assess the wireless OCDMA system performance for any quality of service.