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. 2023 Jul 25;18:211. doi: 10.1186/s13023-023-02811-5

Table 5.

Hospital surgical procedure rates among ACH cases vs controls (CPRD HES-linked cohort)

Procedures by body system Specific procedures
Body system n, ER per 100PY* RR (95% CI) Type n, ER per 100PY* RR (95% CI)
Cases (N = 275) Controls (N = 1064) Cases (N = 275) Controls (N = 1064)
Any procedure 265, 5.15 108, 0.53 9.83 (7.09–13.61)**
Orthopaedic 141, 2.74 53, 0.26 10.63 (6.97–16.22)**
 Spinal 76, 1.48 21, 0.10 14.46 (8.73–23.94)** Spinal decompression 69, 1.34 21, 0.10 13.13 (7.87–21.89)**
Foramen magnum decompression 7, 0.14 0, 0.0 Cases only
 Limb 65, 1.26 32, 0.16 8.10 (4.22–15.56)** Bone fixation† 44, 0.86 11, 0.05 15.99 (7.16–35.75)**
Hip/knee replacement 10, 0.19 21, 0.10 1.90 (0.64–5.67)
Limb lengthening 10, 0.19 0, 0.0 Cases only
Brace provision  < 5, NC 0, 0.0 Cases only
ENT 104, 2.02 48, 0.23 8.62 (5.01–14.82)** Grommet insertion 66, 1.28 20, 0.10 13.15 (5.55–31.17)**
Tonsillectomy/adenoidectomy 23, 0.45 23, 0.11 3.99 (2.25–7.07)**
Hearing Aid 6, 0.12  < 5, NC NC
Tympanoplasty 9, 0.18  < 5, NC NC
Neurological 7, 0.12 0, 0.0 Cases only Shunt/ventriculostomy 7, 0.14 0, 0.0 Cases only
Respiratory 11.0, 0.21  < 5, NC NC Tracheostomy  < 5, NC 0, 0.0 Cases only
Ventilation 10, 0.19  < 5, NC NC
Cardiovascular  < 5, NC  < 5, NC NC Cardiac stent  < 5, NC  < 5, NC NC

ACH Achondroplasia; CI Confidence interval; CPRD Clinical Practice Research Database; ENT Ear, nose and throat; ER Event rate; HES Hospital Episode Statistics; N Total number of individuals; n Number of occurrences of procedure of interest; NC Not calculated (due to small cell size); PY Person years; RR Rate ratio

*Where the number of patients was reported as an integer of more than 0 but less than 5, this has been stated as < 5 due to CPRD reporting requirements

**Statistically significant result (α = 0.05)

Bone fixation procedures were any procedures that involved internal or external bone fixation; for example, fixation related to fracture stabilisation. Bone fixation for limb lengthening was coded under ‘limb lengthening’; however, fractures caused by or associated with limb-lengthening may have been coded under ‘bone fixation’