This is the first study on geographical variation in surgery for pelvic organ prolapse on a national level. 
A previous study has shown a 5-fold variation in the rate of prolapse interventions between 15 countries in the Organization for Economic Cooperation and Development (OECD) (1), which indicates a lack of uniformity in the surgical treatment of women with pelvic organ prolapse. 
Pelvic organ prolapse affects as many as 50% of parous women, with 14% to 19% of women undergoing a surgical correction, thus the surgical management of pelvic organ prolapse is common.
The aims of this study was on a national level i Denmark to: 1) investigate the regional and national operation rates for pelvic organ prolapse (per 10,000 person years) and 2) investigate the geographical variation based on the residence in a subgroup of the included women (age-adjusted).

This is a register-based study. Data were retrieved from the Danish National Registry including women ≥ 18 years with first time surgery for pelvic organ prolapse in the study period from 1996-2012. The registry includes information on all patients discharges from Danish hospitals since 1977. The procedure codes in the Danish National Registry are based on the Nordic Medico-Statistical Commitee (NOMESCO) classification of surgical procedures. In Denmark, the use of grafts is very limited and the usages is amongst the lowest in the world with less than 4% using grafts (1), thus the vast majority of the procedures are native tissue repair.
Denmark has a population of approximately 5.5 million people. All the citizens have free access to a tax supported health care system with less than 5% of prolapse surgeries performed at private hospitals. Denmark was in 2007 organized in 5 different regions: Capital, Zealand, Southern Denmark, Central Jutland and Northern Jutland.

Total number of first time procedures in the study period was 66,677 presenting 30 different procedure codes. The majority of the procedures were cystocele and rectocele operations representing a total of 67% (n = 44,674) of the performed procedures. 
The overall crude national operation rate was 18.2 per 10,000 person years. The regional operations rates ranged from the lowest rate of 12.7 per 10,000 from the Capital Region of Denmark to the highest rate of 21.5 per 10,000 from the region of Northern Jutland.
The distribution of the average annual age-adjusted surgery rate over the country is graphically shown in Figure 1. This is based on the residence of the women at the time of surgery. The distribution was divided in 5 equal groups and is based on standardization of age in a subgroup of women which had surgery performed in 2008-2012. The lightest colour representing the lowest and the darkest colour representing the highest.

We found a wide range in the regional operation rates and a large geographical variation based on the residence of the women. 
The regional differences may lead to discussion among gynecologists performing pelvic organ prolapse surgery in order to investigate possible variations in indications and selection of patient to have a more stable operation rates not based on the residence of the women. Both the international and regional differences demand for the development of uniform guidelines for the surgical treatment of pelvic organ prolapse. We have not investigated the causes of the geographical variation.

In this large national study we found a wide range in the regional operation rates and a large geographical variation based on the residence of the women. The comparison of rates between countries and between regions within countries is important. Such differences reflect both international and national differences in policies, indications for surgery and the selection of patients offered surgery when the women are referred to gynecologists. This should lead to discussion among gynecologists performing these operations in order to investigate possible variations in indications and the selection of patients for surgery.

Haya N, Baessler K, Christmann-Schmid C, et al. Prolapse and continence surgery in countries of the Organization for Economic Cooperation and Development in 2012. Am J Obstet Gynecol 2015;212:755.e1-27