The long-term impact of vaginal surgical mesh devices in UK primary care: a cohort study in the CPRD

Study type
Protocol
Date of Approval
Study reference ID
19_167
Lay Summary

Urinary incontinence is the unintended leakage of urine during normal everyday activities. It affects one in three adult women, but, despite the wide-ranging impact, fewer than 20% are actively treated. While lifestyle and drug treatments are offered in primary care, surgical care recommended if symptoms persist. Mesh implants have been used for 20 years to treat urinary incontinence (UI) and pelvic organ prolapse (POP) (when one or more of the organs in the pelvis (womb/uterus, bladder or top of the vagina) slip down from their normal position and bulge into the vagina).

In response to recent government enquiries, public attention on the complications after mesh procedures, such as infection, pain, depression, anxiety, loss of sex life, and further surgery, has increased. In 2018, the government put an immediate suspension on the use of surgical mesh for UI in England following recommendations by an independent review of the evidence.

Previous studies have described harms treated in the hospital setting. Our study will use data from General Practitioners (GP) and hospital records to describe complications in patients with UI and POP, in the primary care setting, where patients are treated and managed by their GP long after surgery. We will describe complications in those who have and have not had surgical mesh implants. We will also examine whether complications differ in patients of different ages, weights, with different numbers of children or with the surgical speciality. The results will be used to inform future recommendations for patients intervention choices.

Technical Summary

Surgical mesh has been used in urogynaecological procedures to treat stress urinary incontinence (SUI) and pelvic organ prolapse (POP) for the past 20 years. Recent public attention and concerns on complications following mesh in urogynaecological procedures have risen. Such complications may include, pain, infection, depression, anxiety, sexual dysfunction, and further surgery.

The issues with mesh are complex, recommendations differ between national bodies and there is a lack of evidence to inform long term complications.(1) Previous research in the UK has used Hospital Episodes Statistics (HES) data to describe complications (mainly rates of reoperation) related to mesh surgery in the hospital setting. There is a lack of evidence informing comorbidities, workload, prescribing and complications arising in primary care in relation to those who have undergone a procedure.

Therefore this study will use the Clinical Practice Research Datalink (CPRD) linked to HES data to examine the long-term patient outcomes in patients with SUI and/or POP, both with and without surgical mesh implants. Outcomes of interest are grouped into (1) those affecting patient comorbidity and quality of life, such as depression, anxiety and self-harm, and sexual dysfunction, (2) those affecting GP workload, including the number of appointments, referrals, and scans, (3) numbers of prescriptions for antibiotics and for pain relief, and (4) complications. We will describe rates of each outcome stratified by covariates of interest, such as age, body mass index (BMI), parity, those relating to surgery, and other outcomes. We will also fit patient level models (Cox regression for binary variables and, depending on dispersion, Poisson or negative binomial regression for count data) to identify factors that are associated with increased rates of each outcome. Our findings will inform current health policy decisions and shared decision making between patients and clinicians to ensure the safety and management of patients in primary care.

Health Outcomes to be Measured

Four classes of outcomes will be examined, focusing on primary care: comorbidities and quality of life, workload, prescriptions, and complications. These are summarised below, and described in detail in section N (exposures, outcomes and covariates).

Primary outcome:

1. Comorbidities and quality of life:
1.1 depression/anxiety/self harm;
1.2 sexual dysfunction;

Secondary outcomes

2.1 Workload - Use of health services:
2.1.1. number of GP appointments by consultation type (e.g. clinic, surgery, emergency, telephone call, visits etc);
2.1.2. number and type of referrals, including to psychological services and pain clinics/services; and
2.1.3 number and type of scans (MRI, CT scans, transvaginal ultrasounds).

2.2 Prescriptions:
2.2.1 number of prescriptions for antibiotics; and
2.2.2. number of prescriptions for pain relief (opioids).

2.3 Complications
2.3.1. hospital admissions; and
2.3.2 mesh repair/removal surgery
2.3.3 complications of surgery – bladder problems

Collaborators

Emily McFadden - Chief Investigator - University of Oxford
Emily McFadden - Corresponding Applicant - University of Oxford
Carl Heneghan - Collaborator - University of Oxford
Georgia Richards - Collaborator - University of Oxford

Linkages

HES Admitted Patient Care;HES Diagnostic Imaging Dataset;ONS Death Registration Data;Patient Level Index of Multiple Deprivation;Pregnancy Register