Equine Health Update EHU Vol 19 Issue 3 - Page 32

EQUINE | Proceedings aesthesia. The volume of published research on colic has dramatically increased. Research seminars, such as the international colic symposium allow dissemination of novel information and promote discussion on all as- pects relating to colic in the horse Major advances have been made in knowledge of the pathophysiological mechanisms involved with various forms of colic, surgical and anaesthetic techniques and pre- and postoperative critical care of colic patients. There have been significant improvements in inhalant and injectable anaesthetic agents, improved monitor- ing is available and positive inotropic drugs and ventila- tors are routinely used as part of the anaesthetic routine. Additionally, an increase in the pleasure horse popula- tion has seen more horses being regarded as pets and companion animals, more likely to be eligible for surgi- cal treatment. In some regions like the United Kingdom and the Scandinavian countries a greater proportion of the equine population is insured and therefore more cli- ents are prepared to pay for expensive colic surgery. Accurate knowledge of post-operative survival rates for specific forms of colic is an important tool for the clini- cian, when discussing treatment options with the owner of the horse. It is an important factor in the decision- making process in the management of horses with colic as it helps to provide owners with evidence-based infor- mation regarding survival following surgery. Moreover, identification of the specific factors that are significantly associated with prognosis following surgi- cal treatment of colic allows clinicians and owners to make informed decisions regarding the management of individual horses. However, it must be recognized that these key prognostic indicators for survival and survival patterns following surgery, differ between the various types of colic (Archer and Proudman 1996; Traub-Dar- gatz et al. 2001; Kaneene et al. 1997). 32 Outcome Measures Outcome can be defined in different ways. A simple sys- tem is based on the time of survival following surgery and defines a surgical success as a horse walking out of the recovery room after surgery, short term survival as a horse surviving at least to the time of discharge from the hospital, and long term survival as the horse surviv- ing a defined period after leaving the hospital. Variable long term survival times reported in the literature. The types of studies assessing survival of horses follow- ing colic surgery can also vary. Retrospective studies are useful but have a number of limitations. Data may not have been collected on variables of interest, records may be incomplete and valuable data may be missing. Prospective studies are time-consuming and more ex- pensive to perform but the data obtained can be more useful. Study design can often be improved over that of a retrospective study, as potentially issues detrimental to useful data collection can be addressed prior to the initiation of the study. Standard statistical methods can be used for survival analysis such as percentages, proportions, and the comparison between groups of horses. However, these methods cannot investigate effects of other parameters on survival. Therefore more sophisticated statistical methods are utilised using logistic regression and lon- gitudinal studies. The methods include Kaplan-Maier plots, which allow graphical representation of survival and Cox proportional hazards models, which permit looking at the association of specific parameters with survival time. However, a direct comparison of the re- sults from different studies remains difficult due to dif- ferences in inclusion criteria and variat ₯½Έ₯Έ…Ρ•½Ι₯Ν„΄)Ρ₯½Έ½˜…Ν•ΜΈ)Q‘”Ι•ΝΥ±Ρ́ΑΙ•Ν•ΉΡ•‰•±½ά…Ι”΅…₯Ή±δ™Ι½΄U,ΝΡՐ΄)₯•Μ₯ΈΡ‘”U,΅½ΝЁ½˜έ‘₯ έ•Ι”½Ή‘Սѕ…Ёё”)UΉ₯Ω•ΙΝ₯Ρ䁽˜1₯Ω•ΙΑ½½³ŠéM‘½½°½˜Y•Ρ•Ι₯Ή…Ιδ5•‘₯₯Ή”Έ+ŠˆΕΥ₯Ή”!•…±Ρ UΑ‘…Ρ”ƒŠˆ