(2) what the average waiting time for a hip operation in (a) Hemel Hempstead and (b) Hertfordshire was in the latest period for which information is available.
Activity in English NHS hospitals and English NHS commissioned activity in the independent sectorDaysHipKneeMedian waiting timeMean waiting timeMedian waiting timeMean waiting timeEast and North Hertfordshire PCT163146.3167151.6West Hertfordshire PCT141134.2147144.1Notes:Main procedureThe main procedure is the first recorded procedure or intervention in the Hospital Episode Statistics (HES) data set and is usually the most resource intensive procedure or intervention performed during the episode. It is appropriate to use main procedure when looking at admission details, (e.g. time waited), but a more complete count of episodes with a particular procedure is obtained by looking at the main and the secondary procedure.Hip replacement procedures: Total Hip ReplacementOPCS-4.2 codesW37—Total prosthetic replacement of hip joint using cementW38—Total prosthetic replacement of hip joint not using cementW39—Other total prosthetic replacement of hip jointAdditions in OPCS-4.3W37.4—Revision of one component of total prosthetic replacement of hip joint using cementW38.4—Revision of one component of total prosthetic replacement of hip joint not using cementW39.5—Revision of one component of total prosthetic replacement of hip joint NECW39.6—Closed reduction of dislocated total prosthetic replacement of hip jointW93—Hybrid prosthetic replacement of hip joint using cemented acetabular componentW94—Hybrid prosthetic replacement of hip joint using cemented femoral componentW95—Hybrid prosthetic replacement of hip joint using cementHip replacement procedures: Total Prosthetic Replacement of Head of Femur(These codes are included because they are for replacement of part of the hip joint.)OPCS-4.2 codesW46—Prosthetic replacement of head of femur using cementW47—Prosthetic replacement of head of femur not using cementW48—Other prosthetic replacement of head of femurAdditions in OPCS-4.3W48.5—Closed reduction of dislocated prosthetic replacement of head of femurAdditions in OPCS-4.3W40.4—Revision of one component of total prosthetic replacement of knee joint using cementW41.4—Revision of one component of total prosthetic replacement of knee joint not using cement W42.5—Revision of one component of total prosthetic replacement of knee joint NECHemiarthroplasty, unicondylar or unicompartmental knee replacements(These codes are included because they are for replacement of part of the knee joint.)For the following codes (W52-W54) a site code is required in the secondary position. Both codes must be included in the search. The site codes are also listed as follows.OPCS-4.2, 4.3W52—Prosthetic replacement of articulation of other bone using cementW53—Prosthetic replacement of articulation of other bone not using cementW54—Other prosthetic replacement of articulation of other boneThe possible site codes, which would occur in a secondary procedure position (see footnote), are as follows:Z76.5—Lower end of femur NECZ77.4—Upper end of tibia NECZ84.4—Patellofemoral jointZ84.5—Tibiofemoral jointZ84.6—Knee jointSecondary procedureAs well as the main operative procedure, there are up to 11 and 3 prior to 2002-03 secondary operative procedure fields in HES that show secondary or additional procedures performed on the patient during the episode of care.Data qualityHES are compiled from data sent by more than 300 NHS trusts and primary care trusts (PCTs) in England. Data is also received from a number of independent sector organisations for activity commissioned by the English NHS. The NHS Information Centre for health and social care liaises closely with these organisations to encourage submission of complete and valid data and seeks to minimise inaccuracies and the effect of missing and invalid data via HES processes. While this brings about improvement over time, some shortcomings remain.Ungrossed dataFigures have not been adjusted for shortfalls in the data, i.e. the data are ungrossed.Time waited (days)Time waited statistics from HES are not the same as the published waiting list statistics. HES provides counts and time waited for all patients admitted to hospital within a given period, whereas the published waiting list statistics count those waiting for treatment on a specific date and how long they have been on the waiting list. Also, HES calculates the time waited as the difference between the admission and decision to admit dates. Unlike published waiting list statistics, this is not adjusted for self-deferrals or periods of medical/social suspension.PCT/strategic health authority (SHA) data qualityPCT and SHA data was added to historic data years in the HES database using 2002-03 boundaries, as a one-off exercise in 2004. The quality of the data on PCT of treatment and SHA of treatment is poor in 1996-97, 1997-98 and 1998-99, with over a third of all finished episodes having missing values in these years. Data quality of PCT of general practitioner (GP) practice and SHA of GP practice in 1997-98 and 1998-99 is also poor, with a high proportion missing values where practices changed or ceased to exist. There is less change in completeness of the residence-based fields over time, where the majority of unknown values are due to missing postcodes on birth episodes. Users of time series analysis including these years need to be aware of these issues in their interpretation of the data.The PCTs used are as follows:5P3—West Hertfordshire PCT5P4—East and North Hertfordshire PCTMethod of admissionThe method of admission is how the patient was admitted to hospital. When calculating time waited, admissions are elective so the following methods are used:11 Elective—from waiting list12 Elective—bookedCode ‘13 Elective—planned’ is not included as it has been the patients choice to defer.Source:Hospital Episode Statistics (HES), The NHS Information Centre for health and social care