Ten observational studies were included (at least 694 doctors).
Quality: some practices sought to recruit a representative sample for doctors, but some groups were underrepresented in the sample. Most studies used the 'gold' standard method of measuring average consultation time (objective timing of individual consultations). Only one study examined potential confounding factors. Only two studies used a validated instrument to measure the outcome.
Recognition and management of patient problems (2 studies with 3 papers): one study found that faster doctors (average consultation length less than 7 minutes) recognised and dealt with fewer long-term problems than slower doctors (average consultation time 9 minutes or more), (P<0.05); the other study found that patient centredness was associated with average consultation length.
Adherence to agreed criteria for specific conditions (3 studies): one study found that slower doctors met significantly more history and examining audit criteria for hypertension and dysuria, but not for diabetes or general examination. One study found that faster doctors recorded fewer details of history, while another found that female doctors had longer consultations and used more counselling.
Prescribing (5 studies): overall, slower doctors had a lower prescribing rate. One study found that the rate per consultation was 51.5% for slower doctors versus 62.6% for faster doctors (P<0.001). Another study found that the prescribing rates were 54 and 60% for slower and faster doctors, respectively (P<0.001). One study found a positive association between consultation time and prescribing volume. One study found that female doctors had longer consultations and prescribed less. One study found a positive association between a longer consultation time and higher quality of prescribing.
Investigation (3 studies): the studies found different results. One study found that doctors with medium consultation length (2.7 to 3.8 patients per hour) requested fewer blood counts than longer or shorter consultations. One studies found that female general practitioners used more investigations. One study found that faster doctors met more criteria for laboratory tests.
Referral (2 studies): the studies found different results. One study found no difference between faster and slower doctors, while the other found that faster doctors had increased referral rates.
Health promotion (4 studies): the studies suggested that longer consultations increased health promotion activity. One study found that slower doctors offered significantly more preventive care than faster doctors (P<0.001). One study found that slower doctors undertook more preventive procedures during the consultation, but that faster doctors used more preventive interventions that were delegated to a nurse. One study found that female doctors had longer consultations and offered more lifestyle advice. One study found no association between average consultation time and NHS targets for immunisation and cervical cytology.
Follow-up and consultation rates (2 studies): there was some evidence that longer consultations are negatively associated with consultation rate. One study found that slower doctors arranged fewer follow-up consultations (28.5 versus 34.3%, P<0.02) and had fewer reconsultation rates (7.2 versus 12.9%, P<0.001). One study found that patients attending slower doctors consulted them less often.
Patient satisfaction, enablement and 'good consultations' (4 studies): average consultation length was positively associated with some, but not all, elements of patient satisfaction and with patient enablement.
External quality index (1 study): the study found no association between average consultation length and the NHS external quality index.
Doctor stress (1 study): the study found that doctors with a high patient-centred score had longer consultation times and reported increased stress compared with intermediate and low patient centredness doctors.