Table 2.
Rates of skeletal and non-skeletal complications among ACH cases vs controls (CPRD cohort)
| Complications by body system category | Specific complications | ||||||
|---|---|---|---|---|---|---|---|
| Category | n, ER per 100PY* | RR (95% CI) | Specific complication | n, ER per 100PY* | RR (95% CI) | ||
| Cases (N = 541) | Controls (N = 2052) | Cases (N = 541) | Controls (N = 2052) | ||||
| All non-skeletal | 3612, 73.92 | 9903, 41.05 | 1.80 (1.59–2.03)** | – | – | – | – |
| Developmental | 41, 0.84 | 23, 0.10 | 8.84 (4.18–18.72)** | Developmental delay | 16, 0.33 | 9, 0.04 | 8.80 (3.02–25.68)** |
| Speech delay | 20, 0.41 | 13, 0.05 | 7.61 (3.03–19.13)** | ||||
| Motor delay | 5, 0.10 | < 5, NC | NC | ||||
| Neurological | 228, 4.67 | 241, 1.00 | 4.67 (3.21–6.80)** | Incontinence/neurogenic bladder or bowel | 87, 1.78 | 78, 0.32 | 5.54 (3.56–8.63)** |
| Paraplegia/parathesia | 51, 1.04 | 55, 0.23 | 4.58 (2.55–8.22)** | ||||
| Seizures/epilepsy | 39, 0.80 | 80, 0.33 | 2.41 (0.95–6.11) | ||||
| Dementia | 5, 0.10 | 24, 0.10 | 1.02 (0.35–2.98) | ||||
| Hydrocephalus/ventriculomegaly | 42, 0.86 | 0, 0.00 | Cases only | ||||
| Myelopathy | < 5, NC | < 5, NC | NC | ||||
| Failure to thrive | < 5, NC | < 5, NC | NC | ||||
| Subdural haemorrhage/haematoma | < 5, NC | < 5, NC | NC | ||||
| Skeletal | 459, 9.39 | 595, 2.47 | 3.83 (3.02–4.85) | Spinal stenosis/cord compression | 138, 2.82 | 22, 0.09 | 30.52 (16.28 – 57.19)** |
| Spinal deformities | 60, 1.23 | 13, 0.05 | 22.78 (9.99–51.97)** | ||||
| Leg deformity (including genu varum) | 15, 0.31 | 5, 0.02 | 14.39 (5.45–37.99)** | ||||
| Falls | 105, 2.15 | 191, 0.79 | 2.73 (1.84–4.04)** | ||||
| Osteoporosis/osteopenia/reduced BMD | 39, 0.80 | 72, 0.30 | 2.69 (1.44–5.05)** | ||||
| Arthritis/osteoarthritis | 95, 1.94 | 291, 1.21 | 1.65 (1.17–2.31)** | ||||
| Craniocervical stenosis | 7, 0.14 | 0, 0.00 | Cases only | ||||
| Cauda equina syndrome | < 5, NC | < 5, NC | NC | ||||
| ENT | 517, 10.58 | 844, 3.50 | 2.98 (2.43–3.65)** | Hearing loss/deafness | 101, 2.07 | 143, 0.59 | 3.50 (2.50–4.89)** |
| Enlarged tonsils | 13, 0.27 | 18, 0.07 | 3.34 (1.26–8.86)** | ||||
| Otitis media | 365, 7.47 | 565, 2.34 | 3.11 (2.45–3.94)** | ||||
| Voice abnormalities | 8, 0.16 | 16, 0.07 | 2.47 (0.93–6.57) | ||||
| Sinusitis | 25, 0.51 | 101, 0.42 | 1.24 (0.71–2.16) | ||||
| Tracheomalacia/bronchomalacia | < 5, NC | 0, 0.00 | Cases only | ||||
| Middle ear dysfunction/disorder | < 5, NC | < 5, NC | NC | ||||
| Respiratory*** | 144, 2.95 | 250, 1.04 | 2.84 (1.94–4.17)** | Apnoea/sleep disordered breathing | 47, 0.96 | 9, 0.04 | 25.81 (10.00–66.60)** |
| Sleep disorder | 97, 1.99 | 241, 1.00 | 1.98 (1.23–3.19) | ||||
| Metabolic | 326, 6.67 | 984, 4.08 | 1.65 (1.24–2.18)** | Obesity | 213, 4.36 | 424, 1.76 | 2.59 (2.26–2.97)** |
| Hyperlipidaemia | 43, 0.88 | 157, 0.65 | 1.36 (0.88–2.10) | ||||
| Diabetes | 94, 1.92 | 461, 1.91 | 1.00 (0.49–2.06) | ||||
| Mental health | 377, 7.72 | 1156, 4.79 | 1.62 (1.21–2.17)** | Self-harm/suicidal ideation | 9, 0.18 | 12, 0.05 | 3.71 (1.17–11.77)** |
| ADD/ADHD/adjustment disorder | 7, 0.14 | 10, 0.04 | 3.44 (1.13–10.51)** | ||||
| Depression/anxiety | 301, 6.16 | 991, 4.11 | 1.51 (1.09–2.08)** | ||||
| Substance dependence/abuse | 37, 0.76 | 131, 0.54 | 1.40 (0.62–3.18) | ||||
| ‘Other’ mental health issues | 23, 0.47 | 12, 0.05 | 9.07 (1.99–41.30)** | ||||
| Cardiovascular | 565, 11.56 | 2359, 9.78 | 1.17 (0.92–1.49) | Stroke | 7, 0.14 | 23, 0.10 | 1.56 (0.65–3.74) |
| Chest pain/angina | 194, 3.97 | 760, 3.15 | 1.25 (0.96–1.63) | ||||
| Hypertension | 321, 6.57 | 1367, 5.67 | 1.15 (0.80–1.65) | ||||
| Coronary disease | 36, 0.74 | 156, 0.65 | 1.14 (0.57–2.28) | ||||
| Myocardial infarction | 7, 0.14 | 53, 0.22 | 0.66 (0.28–1.58) | ||||
| Other | 1440, 29.47 | 4049, 16.78 | 1.76 (1.52–2.03)** | Pain | 1138, 23.29 | 3047, 12.63 | 1.84 (1.58–2.15)** |
| Gastrointestinal issues | 208, 4.26 | 622, 2.58 | 1.66 (1.31–2.09)** | ||||
| Headache | 75, 1.53 | 264, 1.09 | 1.41 (0.99–2.03) | ||||
| Sexual health/gynaecological issues | 19, 0.39 | 116, 0.48 | 0.79 (0.38–1.63) | ||||
ACH Achondroplasia; ADD Attention deficit disorder; ADHD Attention deficit hyperactivity disorder; BMD Bone mineral density; CI Confidence interval; CPRD Clinical Practice Research Database; ENT Ear, nose and throat; ER Event rate, N Total number of individuals; n Number of cases of complication 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)
***Sleep disorder and apnoea/sleep disordered breathing represent two distinct Read codes; given limited information on what complications would fall under each category, results for these categories have been presented separately